Types of Computer

Computer sizes and power

Computers can be generally classified by size and power as follows, though there is considerable overlap:

• Personal computer: A small, single-user computer based on a microprocessor.


• Workstation: A powerful, single-user computer. A workstation is like a personal computer, but it has a more powerful microprocessor and, in general, a higher-quality monitor.


• Minicomputer: A multi-user computer capable of supporting up to hundreds of users simultaneously.


• Mainframe: A powerful multi-user computer capable of supporting many hundreds or thousands of users simultaneously.


• Supercomputer: An extremely fast computer that can perform hundreds of millions of instructions per second.

Supercomputer and Mainframe

Supercomputer is a broad term for one of the fastest computers currently available. Supercomputers are very expensive and are employed for specialized applications that require immense amounts of mathematical calculations (number crunching). For example, weather forecasting requires a supercomputer. Other uses of supercomputers scientific simulations, (animated) graphics, fluid dynamic calculations, nuclear energy research, electronic design, and analysis of geological data (e.g. in petrochemical prospecting). Perhaps the best known supercomputer manufacturer is Cray Research.

Mainframe was a term originally referring to the cabinet containing the central processor unit or "main frame" of a room-filling Stone Age batch machine. After the emergence of smaller "minicomputer" designs in the early 1970s, the traditional big iron machines were described as "mainframe computers" and eventually just as mainframes. Nowadays a Mainframe is a very large and expensive computer capable of supporting hundreds, or even thousands, of users simultaneously. The chief difference between a supercomputer and a mainframe is that a supercomputer channels all its power into executing a few programs as fast as possible, whereas a mainframe uses its power to execute many programs concurrently. In some ways, mainframes are more powerful than supercomputers because they support more simultaneous programs. But supercomputers can execute a single program faster than a mainframe. The distinction between small mainframes and minicomputers is vague, depending really on how the manufacturer wants to market its machines.

Minicomputer

It is a midsize computer. In the past decade, the distinction between large minicomputers and small mainframes has blurred, however, as has the distinction between small minicomputers and workstations. But in general, a minicomputer is a multiprocessing system capable of supporting from up to 200 users simultaneously.

Workstation

It is a type of computer used for engineering applications (CAD/CAM), desktop publishing, software development, and other types of applications that require a moderate amount of computing power and relatively high quality graphics capabilities. Workstations generally come with a large, high-resolution graphics screen, at large amount of RAM, built-in network support, and a graphical user interface. Most workstations also have a mass storage device such as a disk drive, but a special type of workstation, called a diskless workstation, comes without a disk drive. The most common operating systems for workstations are UNIX and Windows NT. Like personal computers, most workstations are single-user computers. However, workstations are typically linked together to form a local-area network, although they can also be used as stand-alone systems.

N.B.: In networking, workstation refers to any computer connected to a local-area network. It could be a workstation or a personal computer.

Personal computer:

It can be defined as a small, relatively inexpensive computer designed for an individual user. In price, personal computers range anywhere from a few hundred pounds to over five thousand pounds. All are based on the microprocessor technology that enables manufacturers to put an entire CPU on one chip. Businesses use personal computers for word processing, accounting, desktop publishing, and for running spreadsheet and database management applications. At home, the most popular use for personal computers is for playing games and recently for surfing the Internet.

Personal computers first appeared in the late 1970s. One of the first and most popular personal computers was the Apple II, introduced in 1977 by Apple Computer. During the late 1970s and early 1980s, new models and competing operating systems seemed to appear daily. Then, in 1981, IBM entered the fray with its first personal computer, known as the IBM PC. The IBM PC quickly became the personal computer of choice, and most other personal computer manufacturers fell by the wayside. P.C. is short for personal computer or IBM PC. One of the few companies to survive IBM's onslaught was Apple Computer, which remains a major player in the personal computer marketplace. Other companies adjusted to IBM's dominance by building IBM clones, computers that were internally almost the same as the IBM PC, but that cost less. Because IBM clones used the same microprocessors as IBM PCs, they were capable of running the same software. Over the years, IBM has lost much of its influence in directing the evolution of PCs. Therefore after the release of the first PC by IBM the term PC increasingly came to mean IBM or IBM-compatible personal computers, to the exclusion of other types of personal computers, such as Macintoshes. In recent years, the term PC has become more and more difficult to pin down. In general, though, it applies to any personal computer based on an Intel microprocessor, or on an Intel-compatible microprocessor. For nearly every other component, including the operating system, there are several options, all of which fall under the rubric of PC

Today, the world of personal computers is basically divided between Apple Macintoshes and PCs. The principal characteristics of personal computers are that they are single-user systems and are based on microprocessors. However, although personal computers are designed as single-user systems, it is common to link them together to form a network. In terms of power, there is great variety. At the high end, the distinction between personal computers and workstations has faded. High-end models of the Macintosh and PC offer the same computing power and graphics capability as low-end workstations by Sun Microsystems, Hewlett-Packard, and DEC.

III, Personal Computer Types

Actual personal computers can be generally classified by size and chassis / case. The chassis or case is the metal frame that serves as the structural support for electronic components. Every computer system requires at least one chassis to house the circuit boards and wiring. The chassis also contains slots for expansion boards. If you want to insert more boards than there are slots, you will need an expansion chassis, which provides additional slots. There are two basic flavors of chassis designs–desktop models and tower models–but there are many variations on these two basic types. Then come the portable computers that are computers small enough to carry. Portable computers include notebook and subnotebook computers, hand-held computers, palmtops, and PDAs.

Tower model

The term refers to a computer in which the power supply, motherboard, and mass storage devices are stacked on top of each other in a cabinet. This is in contrast to desktop models, in which these components are housed in a more compact box. The main advantage of tower models is that there are fewer space constraints, which makes installation of additional storage devices easier.

Desktop model

A computer designed to fit comfortably on top of a desk, typically with the monitor sitting on top of the computer. Desktop model computers are broad and low, whereas tower model computers are narrow and tall. Because of their shape, desktop model computers are generally limited to three internal mass storage devices. Desktop models designed to be very small are sometimes referred to as slimline models.

Notebook computer

An extremely lightweight personal computer. Notebook computers typically weigh less than 6 pounds and are small enough to fit easily in a briefcase. Aside from size, the principal difference between a notebook computer and a personal computer is the display screen. Notebook computers use a variety of techniques, known as flat-panel technologies, to produce a lightweight and non-bulky display screen. The quality of notebook display screens varies considerably. In terms of computing power, modern notebook computers are nearly equivalent to personal computers. They have the same CPUs, memory capacity, and disk drives. However, all this power in a small package is expensive. Notebook computers cost about twice as much as equivalent regular-sized computers. Notebook computers come with battery packs that enable you to run them without plugging them in. However, the batteries need to be recharged every few hours.

Laptop computer

A small, portable computer -- small enough that it can sit on your lap. Nowadays, laptop computers are more frequently called notebook computers.

Subnotebook computer

A portable computer that is slightly lighter and smaller than a full-sized notebook computer. Typically, subnotebook computers have a smaller keyboard and screen, but are otherwise equivalent to notebook computers.

Hand-held computer

A portable computer that is small enough to be held in one’s hand. Although extremely convenient to carry, handheld computers have not replaced notebook computers because of their small keyboards and screens. The most popular hand-held computers are those that are specifically designed to provide PIM (personal information manager) functions, such as a calendar and address book. Some manufacturers are trying to solve the small keyboard problem by replacing the keyboard with an electronic pen. However, these pen-based devices rely on handwriting recognition technologies, which are still in their infancy. Hand-held computers are also called PDAs, palmtops and pocket computers.

Palmtop

A small computer that literally fits in your palm. Compared to full-size computers, palmtops are severely limited, but they are practical for certain functions such as phone books and calendars. Palmtops that use a pen rather than a keyboard for input are often called hand-held computers or PDAs. Because of their small size, most palmtop computers do not include disk drives. However, many contain PCMCIA slots in which you can insert disk drives, modems, memory, and other devices. Palmtops are also called PDAs, hand-held computers and pocket computers.

PDA

Short for personal digital assistant, a handheld device that combines computing, telephone/fax, and networking features. A typical PDA can function as a cellular phone, fax sender, and personal organizer. Unlike portable computers, most PDAs are pen-based, using a stylus rather than a keyboard for input. This means that they also incorporate handwriting recognition features. Some PDAs can also react to voice input by using voice recognition technologies. The field of PDA was pioneered by Apple Computer, which introduced the Newton MessagePad in 1993. Shortly thereafter, several other manufacturers offered similar products. To date, PDAs have had only modest success in the marketplace, due to their high price tags and limited applications. However, many experts believe that PDAs will eventually become common gadgets.

PDAs are also called palmtops, hand-held computers and pocket computers.

Top 50 Mainframe Interview Questions

1. What is DRDA ?
DRDA stands for Distributed Relational Database Architecture. DRDA is a connection protocol for relational database processing which IBM and vendor databases use. It consists of rules for communication between a remote relational DBMS and the application.
2. Explain the use of the WHERE?
The “WHERE” clause isolates an element or row whenever it is used with a relational statement.
3. How can a LIKE table be created?
It can be made by the use of the LIKE parameter in the statement CREATE. These tables are generally required for testing the production environment.
4. What is the need of running runstats in the test environment?
It is for clearing the default values from the catalog columns. Because if the columns have default values; then the result might not be an expected one.
5. What is the need of a secondary index in IMS?
It is a substitute path into any IMS database. It can be used as a file to acquire required data.

Mainframe

6. Explain foreign keys?
Foreign keys are properties of a particular table having matching entries to a primary key in some another table. This results in the formation of a relation between the two tables.
7. Write about the self-referencing constraint?
It limits the changes that can be made to the primary key from a foreign key. For this purpose, the foreign key has to define a DELETE CASCADE rule.
8. What does a deadlock mean in DB2?

When two independent processes contend for the same resource or the resources reserved by one another, it is called a deadlock. -911 and -913 are the SQLcode for a deadlock.
9. What is the function of DBCTL?
It is used to access IMS files for CICS Transactions and it is an address space. PSBs, DBDs, IMS files and ACBs are fixed into DBCTL for file access. Now if an IMS call is generated by a CICS program the processing gets transferred to DBCTL to be carried, and the result is sent as reply.
10. How are TYPE 1 and TYPE 2 indexes different?
TYPE 2 index is available for DB2V4. In this type, the data pages get locked, but the index pages are not locked. Therefore, TYPE 2 index are faster.
11. What are the different types of Table spaces?
There are three table spaces, namely:

• Simple
• Segmented
• Partitioned

12. Write the difference between HIDAM and HDAM databases?
HIDAM has a separate index file which is based on the root segment. This file has information regarding the pointer that marks the position of the data. On the other hand, HDAM file does not have separate index file, but the key field of every record is passed through a randomizer which places the record to a particular position in the database.
13. Explain referential integrity?
It is the rule that states that consistency needs to be conserved between the foreign and primary keys. This means that each foreign key entry needs to have a fitting primary key entry.
14. How are composite and multiple indexes different?
Multiple index are two indexes, one each for a column of the same table. Composite index is only one index, which consists of combined values of 2 columns of a table.
15. What is the advantage in De-normalizing tables in DB2?
It lowers the requirement for executing intensive relational joins. It also cuts the number of required foreign keys.
16. Explain Database Descriptor in brief?
DBD, short for Database Descriptor, restricts access to the database when objects get altered, created or dropped.
17. State the maximum value up to which volumes can be inserted to an STOGROUP?
Volumes can be inserted up to 133. Practically though, only 3-4 volumes, when added to an STOGROUP, becomes hard to manage and monitor.
18. Explain delete-connected tables?
Tables, which are related through a foreign key, are known as delete-connected tables. This is because whenever any entry in the primary key is deleted, it affects the values in the foreign key table too.
19. Explain lock contention?
The DBD only allows entry to one object at a particular time. Lock contention is said to happen when more than one object seeks permission for execution simultaneously.
20. What is SPUFI?
SPUFI is the abbreviated form of SQL Processing Using File Input. It is a menu-driven tool which the developers use to make objects in the database.
21. What is an alias?
It is a substitute to a synonym. Aliases are developed for distributed environments so as to avoid the use of location qualifier of a view or table. It is not dropped when the table gets deleted.
22. What is the place for VSAM KSDS?
It is the BSDS.
23. Name and explain the type of locks?

There are three types of lock, namely:

• Shared – This type of lock permits two or more programs to read from the locked space but does not allow them to change it.
• Update – This lock is more lenient. It permits the program to read and change the locked space.
• Exclusive – This lock restricts all users from accessing the locked space.

24. Explain isolation level?
Isolation level is the degree to which the activation group in focus is isolated from the activation groups executing at the same time.
25. What is NOTCAT2?
It is an MVS message that indicates the presence of a duplicate catalogue in the database. This problem can be fixed by removing one of the entries and then adding a new one.
26. What will happen if both STEPLIB and JOBLIB are specified?
JOBLIB is a Data Definition statement. It determines the location of the program, which called the EXEC statement. JOBLIB applies to all steps present in that whole job. It is not possible to use it for catalogued procedures. STEPLIB is very similar JOBLIB. It determines the dataset in which the program exists. It applies only to one step and not the entire job. STEPLIB can be used at any position in the job step and can also be used for catalogued procedures.
In a situation when both STEPLIB and JOBLIB are specified, JOBLIB will be ignored by the system.
27. State the difference between JES2 and JES3?
In JES3, the allocation of data sets for the steps takes place even before the job is scheduled for execution. While in JES2, this allocation takes place just before the execution of each step.
28. State all the File OPEN modes?
The four File Open methods are:

• INPUT
• OUTPUT
• EXTEND
• I-O

29. Is the order of the WHEN clause significant in an EVALUATE statement?
Yes, the order is significant as the evaluation takes place in the top to bottom manner and, therefore, the order has a large impact in the determination of results.
30. When are scope terminators compulsory?
They are compulsory for EVALUATE statements and in-line PERFORMS.  Scope terminators are always declared explicitly to improve readability.
31. What is linkage section?
It is a part of a program that is being called and maps to data items in the program’s (calling) working storage. Linkage Sections is where shared items are declared and defined.
32. How is NEXT SENTENCE and CONTINUE different?
The NEXT SENTENCE hands the flow of control to the statement that follows the next period. On the other hand, CONTINUE hands the flow of control to the next statement after the scope terminator.
33. What is the need to code COMMITS in batch programs?
COMMIT statements are used to release locks which are required for that unit of work, and then permit a new unit of work. In other words, if COMMITS are not coded in the program and the program has been sent for execution, then while processing, in place of just going back to a few inserts since the nearest commit, the program has to go back to the inserts which were made during the entire run of the program. This extra process takes around twice or thrice the time taken normally.
34. How is data retrieved from multiple tables using a single SQL statement?
Data can be retrieved from multiple tables by using joins, nested selects and unions.
35. Write about a ‘view’ in brief?
It is a virtual table that is made using data from base tables and other views. This table is not stored separately.
36. What parameters are used to control the free space in DB2?
Free space permits the addition of new rows.
There are two parameters, which are used to control the free space in DB2, they are:

• PCTFREE – It defines the free space percentage that will be present in each page.
• FREEPAGE – It specifies the number of pages to be loaded before leaving a page empty.

37. What is the function of CURRENTDATA option in bind?
It allows block fetch when selecting rows in a table. It is set to NO by default from DB2V4. So it is important to change CURRENTDATA (YES), in the bind cards, to NO in DB2V3 & earlier, as YES is the default value for them.
38. How can record locking be achieved in those DB2 versions which do not support it?
It can be done by setting the record length’s size to more than half of the page’s size.
39. State the maximum number of tables that can be joined?
The maximum numbers of tables that can be joined are fifteen.
40. Explain index cardinality?
Index cardinality is the number of discrete entries in a column. In DB2, a utility RUNSTATS examines the column value redundancy to find if an index scan or tablespace is required for searching of data.
41. Define clustered index?
A clustered index is the one in which columns are maintained in the same sequence as the rows until there is still free space in the memory. DB2 then processes the table in the given order expeditiously.
42. Name the lockable units in DB2?
DB2 implements locking on four types of units:

• Pages
• Indexes sub page
• Tables
• Table space

43. What is the function of the verb INITIALIZE?
This verb sets Alphanumeric, alphabetic and alphanumeric field items to ““(Space) and Numeric and Numeric edited field items to “0” (Zero). The INITIALIZE verb leaves FILLER items unchanged.
44. What is the importance of COMMON Attribute?
Its functions are utilized in nested COBOL programs. If COMMON attribute will not be specified, the nested programs will find it impossible to access the program. An example of COMMON program is Pgmname.
45. What will be the result if ON SIZE ERROR phrase is declared?
When the condition is true, the code written in the “ON SIZE ERROR” phrase is performed. During this process, the content of the destination field does not change.
If this phrase is not mentioned, then the statement is executed with truncation. MOVE statement does not support the ON SIZE ERROR phrase.
46. Can records be accessed randomly in ESDS?
Yes, records can be accessed randomly. It can be done by reference of Relative Byte Address (RBA). However, it is not possible to delete records.
47. Why is free space left in KSDS Dataset?
While allocating KSDS Datasets, free space is declared at regular intervals at the time of initial loading. This is done because this free space is utilized for keeping the data arranged in sequence physically, even though inserted randomly.
48. Write in brief about clusters?
It is a combination consisting of the sequence set, index and data portions in the Data set. The cluster has the program access given to it by the Operating System, and this allows access to be granted to all parts of the Dataset at the same time.
49. Explain path?
It is a file that makes accessing a file by alternate index possible. The path defines a relation between the base cluster and the AIX.
50. What is the function of IEBGENER?
IEBGENER helps in copying one SAM File to some other Source. It is also used to perform simple data reformatting through the supply of control cards via SYSIN.

Top 50 Operating System Interview Questions & Answers

1) Explain the main purpose of an operating system?
Operating systems exist for two main purposes. One is that it is designed to make sure a computer system performs well by managing its computational activities. Another is that it provides an environment for the development and execution of programs.

2) What is demand paging?
Demand paging is referred when not all of a process’s pages are in the RAM, then the OS brings the missing(and required) pages from the disk into the RAM.
3) What are the advantages of a multiprocessor system?
With an increased number of processors, there is considerable increase in throughput. It can also save more money because they can share resources. Finally, overall reliability is increased as well.
4) What is kernel?
Kernel is the core of every operating system. It connects applications to the actual processing of data. It also manages all communications between software and hardware components to ensure usability and reliability.
5) What are real-time systems?
Real-time systems are used when rigid time requirements have been placed on the operation of a processor. It has well defined and fixed time constraints.
6) What is virtual memory?
Virtual memory is a memory management technique for letting processes execute outside of memory. This is very useful especially is an executing program cannot fit in the physical memory.
7) Describe the objective of multiprogramming.
The main objective of multiprogramming is to have process running at all times. With this design, CPU utilization is said to be maximized.

8 ) What are time sharing systems?
In a Time sharing system, the CPU executes multiple jobs by switching among them, also known as multitasking. This process happens so fast that users can actually interact with each program while it is running.
9) What is SMP?
SMP is short for Symmetric MultiProcessing, and is the most common type of multiple-processor systems. In this system, each processor runs an identical copy of the operating system, and these copies communicate with one another as needed.
10) How are server systems classified?
Server systems can be classified as either computer-server systems or file server systems. In the first case, an interface is made available for clients to send requests to perform an action. In the second case, provisions are available for clients to create, access and update files.
11) What is asymmetric clustering?
In asymmetric clustering, a machine is in a state known as hot standby mode where it does nothing but to monitor the active server. That machine takes the active server’s role should the server fails.
12) What is a thread?
A thread is a basic unit of CPU utilization. In general, a thread is composed of a thread ID, program counter, register set and the stack.
13) Give some benefits of multithreaded programming.
– there is an increased responsiveness to the user
– resource sharing within the process
– economy
– utilization of multiprocessing architecture
14) Briefly explain FCFS.
FCFS is short for First-come, first-served, and is one type of scheduling algorithm. In this scheme, the process that requests the CPU first is allocated the CPU first. Implementation is managed by a FIFO queue.
15) What is RR scheduling algorithm?
RR (round-robin) scheduling algorithm is primarily aimed for time-sharing systems. A circular queue is setup in such a way that the CPU scheduler goes around that queue, allocating CPU to each process for a time interval of up to around 10 to 100 milliseconds.
16) What necessary conditions can lead to a deadlock situation in a system?
Deadlock situations occur when four conditions occur simultaneously in a system: Mutual exclusion; Hold and Wait; No preemption; and Circular wait.
17) Enumerate the different RAID levels.
RAID 0 – Non-redundant striping
RAID 1 – Mirrored Disks
RAID 2 – Memory-style error-correcting codes
RAID 3 – Bit-interleaved Parity
RAID 4 – Block-interleaved Parity
RAID 5 – Block-interleaved distributed Parity
RAID 6 – P+Q Redundancy
18) Describe Banker’s algorithm

Bankers Algorithm

Banker’s algorithm is one form of deadlock-avoidance in a system. It gets its name from a banking system wherein the bank never allocates available cash in such a way that it can no longer satisfy the needs of all of its customers.
19) What factors determine whether a detection-algorithm must be utilized in a deadlock avoidance system?
One is that it depends on how often a deadlock is likely to occur under the implementation of this algorithm. The other has to do with how many processes will be affected by deadlock when this algorithm is applied.
20) Differentiate logical from physical address space.
Logical address refers to the address that is generated by the CPU. On the other hand, physical address refers to the address that is seen by the memory unit.
21) How does dynamic loading aid in better memory space utilization?
With dynamic loading, a routine is not loaded until it is called. This method is especially useful when large amounts of code are needed in order to handle infrequently occurring cases such as error routines.
22) What are overlays?
Overlays are used to enable a process to be larger than the amount of memory allocated to it. The basic idea of this is that only instructions and data that are needed at any given time are kept in memory.
23) What is the basic function of paging?
Paging is a memory management scheme that permits the physical-address space of a process to be noncontiguous. It avoids the considerable problem of having to fit varied sized memory chunks onto the backing store.
24) What is fragmentation?
Fragmentation is memory wasted. It can be internal if we are dealing with systems that have fixed-sized allocation units, or external if we are dealing with systems that have variable-sized allocation units.
25) How does swapping result in better memory management?
During regular intervals that are set by the operating system, processes can be copied from main memory to a backing store, and then copied back later. Swapping allows more processes to be run that can fit into memory at one time.
26) Give an example of a Process State.
– New State – means a process is being created
– Running – means instructions are being executed
– Waiting – means a process is waiting for certain conditions or events to occur
– Ready – means a process is waiting for an instruction from the main processor
– Terminate – means a process is done executing
27) What is a socket?
A socket provides a connection between two applications. Each endpoint of a communication is a socket.
28) What is Direct Access Method?
Direct Access method is based on a disk model of a file, such that it is viewed as a numbered sequence of blocks or records. It allows arbitrary blocks to be read or written. Direct access is advantageous when accessing large amounts of information.
29) When does thrashing occur?
Thrashing refers to an instance of high paging activity. This happens when it is spending more time paging instead of executing.
30) What is the best page size when designing an operating system?
The best paging size varies from system to system, so there is no single best when it comes to page size. There are different factors to consider in order to come up with a suitable page size, such as page table, paging time, and its effect on the overall efficiency of the operating system.
31) When designing the file structure for an operating system, what attributes are considered?
Typically, the different attributes for a file structure are naming, identifier, supported file types, and location for the files, size, and level of protection.
32) What is root partition?
Root partition is where the operating system kernel is located. It also contains other potentially important system files that are mounted during boot time.
33) What are device drivers?
Device drivers provides a standard means of representing I/O devices that maybe manufactured by different companies. This prevents conflicts whenever such devices are incorporated in a systems unit.
34) What are the primary functions of VFS?
VFS, or Virtual File System, separates file system generic operations from their implementation by defining a clean VFS interface. It is also based on a file-representation structure known as vnode, which contains a numerical designator needed to support network file systems.
35) What are the different types of CPU registers in a typical operating system design?
– Accumulators
– Index Registers
– Stack Pointer
– General Purpose Registers
36) What is the purpose of an I/O status information?
I/O status information provides info about which I/O devices are to be allocated for a particular process. It also shows which files are opened, and other I/O device state.
37) What is multitasking?
Multitasking is the process within an operating system that allows the user to run several applications at the same time. However, only one application is active at a time for user interaction, although some applications can run “behind the scene”.
38) What are some pros and cons of a command line interface?

A command line interface allows the user to type in commands that can immediately provide results. Many seasoned computer users are well accustomed to using the command line because they find it quicker and simpler. The main problem with a command line interface is that users have to be familiar with the commands, including the switches and parameters that come with it. This is a downside for people who are not fond of memorizing commands.
39) What is caching?
Caching is the processing of utilizing a region of fast memory for a limited data and process. A cache memory is usually much efficient because of its high access speed.
40) What is spooling?
Spooling is normally associated with printing. When different applications want to send an output to the printer at the same time, spooling takes all of these print jobs into a disk file and queues them accordingly to the printer.
41) What is an Assembler?
An assembler acts as a translator for low level language. Assembly codes, written using mnemonic commands are translated by the Assembler into machine language.
42) What are interrupts?
Interrupts are part of a hardware mechanism that sends a notification to the CPU when it wants to gain access to a particular resource. An interrupt handler receives this interrupt signal and “tells” the processor to take action based on the interrupt request.
43) What is GUI?
GUI is short for Graphical User Interface. It provides users with an interface wherein actions can be performed by interacting with icons and graphical symbols. People find it easier to interact with the computer when in a GUI especially when using the mouse. Instead of having to remember and type commands, users just click on buttons to perform a process.
44) What is preemptive multitasking?
Preemptive multitasking allows an operating system to switch between software programs. This in turn allows multiple programs to run without necessarily taking complete control over the processor and resulting in system crashes.
45) Why is partitioning and formatting a prerequisite to installing an operating system?
Partitioning and formatting creates a preparatory environment on the drive so that the operating system can be copied and installed properly. This includes allocating space on the drive, designating a drive name, determining and creating the appropriate file system structure.
46) What is plumbing / piping?
It is the process of using the output of one program as an input to another. For example, instead of sending the listing of a folder or drive to the main screen, it can be piped and sent to a file, or sent to the printer to produce a hard copy.
47) What is NOS?
NOS is short for Network Operating System. It is a specialized software that will allow a computer to communicate with other devices over the network, including file/folder sharing.
48) Differentiate internal commands from external commands.
Internal commands are built-in commands that are already part of the operating system. External commands are separate file programs that are stored in a separate folder or directory.
49) Under DOS, what command will you type when you want to list down the files in a directory, and at the same time pause after every screen output?
a) dir /w
b) dir /p
c) dir /s
d) dir /w /p
Answer: d) dir /w /p
50) How would a filenamed EXAMPLEFILE.TXT appear when viewed under the DOS command console operating in Windows 98?
The filename would appear as EXAMPL~1.TXT . The reason behind this is that filenames under this operating system is limited to 8 characters when working under DOS environment.
51) What is a folder in Ubuntu ?
There is no concept of Folder in Ubuntu. Everything including your hardware is a FILE
52) Explain why Ubuntu is safe and not affected by viruses?

• It does not support malicious e-mails and contents, and before any e-mail is opened by users it will go through many security checks
• Ubuntu uses Linux , which is a super secure O.S system
• Unlike other O.S, countless Linux users can see the code at any time and can fix the problem if there is any
• Generally, Malwares and viruses are coded to take advantage of weakness in Windows

53) Explain what is Unity in Ubuntu ? How can you add new entries to the launcher?
In Ubuntu, Unity is the default windows manager.  On left side of the Ubuntu it introduces the launcher and Dash to start programs.
In order to add new entries to the launcher you can create a file name like .desktop and  then drag file on the launcher.
54) Explain what is the purpose of using libaio package in Ubuntu?
Libaio is Linux Kernel Asynchronous I/O (A/O).  A/O allows even a single application thread to overlap I/O operations with other processing, by providing an interface for submitting one or more I/O requests in one system call without waiting for completion.  And a separate interface to reap completed I/O operations associated with a given completion group.
55) What is the use of behaviour tab in Ubuntu?
Through behaviours tab you can make many changes on the appearance of desktop

• Auto hide the launcher : You can use this option to reveal the launcher when moving the pointer to the defined hot spot.
• Enable workspaces:  By checking this option you can enable workspace
• Add show desktop icon to the launcher: This option is used to display the desktop icon on the launcher

56) Explain what is the meaning of “export” command in Ubuntu?
Export is a command in Bash shell language, when you try to set a variable, it is visible or exported to any subprocess started from that instance of bash.  The variable will not exist in the sub-process without the export command.
57) Explain how you can reset Unity Configuration?
To reset the unity configuration the simplest way to do is to hit open a Terminal or hit Atl-F2  and run the command # unity –reset
58) Explain how to access Terminal?
To access terminal , you have to go under Application Menu -> Accessories -> Terminal .

Operating System Quiz

Top 21 Computer Architecture Interview Questions

1) Explain what is Computer Architecture?
Computer architecture is a specification detailing about how a set of software and hardware standards interacts with each other to form a computer system or platform.
2) How Computer Architecture is characterized?
The computer architecture is characterized into three categories

• System Design: It includes all the hardware component in the system, including data processor aside from the CPU like direct memory access and graphic processing unit
• Instruction Set Architecture (ISA): It is the embedded programming language of the central processing unit. It determines the CPU’s functions and capabilities based on programming it can process.
• Microarchitecture: It defines the data path, storage element, and data processing as well as how they should be implemented in the ISA.

3) Mention important steps for computer design?
A CPU architecture is defined by the set of machine language which can be defined as a

• Set of registers and their functions ( capabilities )
• Sequence of micro-operations performed on the data stored in registers
• Control signals that initiate the sequence

4) Mention what are the different types of fields that are part of an instruction?
The different types of fields that are parts of an instruction are

• Operation Code Field or OP Code field: This field is used to determine the operation to be performed for the instruction
• Address Field: This field is used to determine various addresses such as memory address and register address
• Mode Field: This field determines how operand is to perform or how effective address is derived

5) Mention what are the basic components of a Microprocessor?
The basic components of a Microprocessor are

• Address lines to refer to the address of a block
• Data lines for data transfer
• IC chips for processing data

6) Mention what are different types of interrupts in a microprocessor system? Explain?
There are three types of interrupts that can cause a break.

• External Interrrupts:

From external input/output devices such types of interrupt comes.

• Internal Interrupts:

These types of interrupts are caused due to any exception caused by the program itself. For example, division by zero or an invalid opcode, etc.

• Software Interrupts:

Only during the execution of an instruction such type of interruption can occur.  The primary purpose of such interrupts is to switch from user mode to supervisor mode.
7) Mention what are the common components of a microprocessor are?
The common components of a microprocessor include

• I/O Units
• Control Unit
• Arithmetic Logic Unit (ALU)
• Registers
• Cache

8) Explain what is Snooping Cache?

Snooping Cache is the process where individual caches monitor address lines for accesses to memory locations that they have cached.
9) Mention what is the simplest way to determine cache locations in which to store memory blocks?
Direct Mapping is the simplest way to define cache locations in which to store memory blocks. Associative memories are expensive in comparison to random-access memories due to the added logic associated with each cell.
10) What digital functions should be used to convert the octal code to binary code?
To convert the octal code to binary code multiplexers is used. It is also referred as Data Selector, where dynamic memory uses the same address lines for both row and column.
11) What technique is used to automatically move program and data blocks into the physical main memory when they are required for execution?
Virtual Memory technique is used. It provides a mechanism for translating program generated address into correct main memory locations.  By means of mapping table translation or mapping is handled.
12) Mention what is the use of RAID system?
The use of RAID system is to increase the disk storage capacity and availability.
13) Explain what type of memory that can be erased with the electric discharge?
With the passage of electric discharge, EEPROM is the type of memory whose content is erased.
14) Explain what is horizontal micro code?
The horizontal micro code contains the control signal without any intermediary.  It contains a lot of signals and hence due to that the number of bits also increases.
15) Explain what is direct mapping?
In direct mapping, the RAM is used to store data and some of the data is stored in the Cache.  The address space is divided into two parts index field and tag field.  The tag field is used to store the tag field whereas the rest is stored in the main memory.
16) Mention what are the types of micro-operations?
The types of micro-operations are

• Register transfer micro-operations: These type of micro-operations are used to transfer information from one register to another binary information
• Shift micro-operation: These operations are used to perform shift operations in data store in registers
• Logic micro-operation: These are used to perform on numeric data stored in the registers some arithmetic operations
• Arithmetic micro-operations: These micro-operations are used to execute some arithmetic operations on numeric data stored in the registers

17) What does DMA stands for?
DMA stands for Direct Memory Access.
18) When large number of registers are included in the CPU, what is the most efficient way to connect them?
When large number of registers are included in the CPU, the most efficient way to connect them is through an ALU.
19) Explain if the internal bus connects only register within the CPU, how would you get data to and from memory?
The AR or Address Register is used to select a memory address, and the Data Register is used to send and receive the data.  Both these register are connected to the internal BUS, and the Data Register acts as a bridge between the memory data BUS and internal BUS.
So first we load AR with the desired memory address and then transfer to or from Data Register.
20) Explain what is WAIT state?
A WAIT state plays a key role in preventing CPU speed incompatibilities.  Many times the processor is at ready state to accept data from a device or location, but there might be no input available. In such case there will be wastage of CPU time, and the system gets into WAIT state.
21) Explain how you can deal with WAIT state?
The one way to deal with WAIT state is increasing the microprocessor clock period by reducing the clock frequency
The second way is by using special control input READY. It allows the memory to set its own memory cycle time.

Top 25 Technical Support Interview Questions & Answers

1) Name some of the latest Computer Processors?
Intel Pentium Quad Core, Intel I3, I5 and I7 processor are some of the latest Computer Processor.
2) What does a ‘?’ sign in device manager indicate?
When this sign appears, it indicates the device is not properly installed.  Such problem arises in case of brand new plug-in cards.
3) How will you cope up with a customer, who complains about a brand new printer and system, and yet failing to get a proper print copy?
The first thing I will ask the customer, whether the system is properly connected with the printer. The next thing would be to check the Device Driver. Many times it happens that if you install an incorrect Device Driver, the print copy would not be clear.
4) How you keep yourself updated with the current technology?
I keep myself connected with social networking sites, the first platform for any technological advancement news and also keep surfing on the latest technology on internet.
5) What are the tools that will be helpful to you in identifying the problems and solving them?
Manuals, Knowledge, team-members and experience are the tools that will be helpful to trouble shoot the problem and solving them.

Tech Support

6) What is the expected period of an average call while dealing with the customers?
The expected period of an average call would be around 2-3 minutes, sometimes less or more depending on the problem complexity.
7) Why 8085 processor is called 8 bit processor?
It is called 8 bit processor as it has 8 bit ALU (Arithmetic Logic Unit).

8) What is stack and can we use ROM as stack?
Stack is a portion of RAM used for saving the content of the program counter and general purpose registers.  ROM cannot be used as a stack, as it is not possible to write on ROM.
9) What does it mean by interrupt?
To perform a particular task, interrupt is a signal send by external device to the processor.
10) What is a Microprocessor?
A microprocessor is a program controlled device. It retrieves the data instructions from memory and decodes them, after decoding, it executes the instruction.
11) What is Latch?
It is a temporary storage device controlled by a timing signal, which can store 1 or 0.  It is a D-type flip flop storage device.
12) What is the disadvantage of microprocessor?

It has a limitation on the size of the data, also most microprocessor does not support floating point operations.
13) What do you mean by DHCP?
DHCP stands for Dynamic Host Configuration Protocol, it is a network protocol, and it enables the server to assign automatically, IP address to a computer.
14) What do you mean by OSI?
OSI stands for open system interconnection.  It is a standard description or a reference model of how message should be conveyed between any two points within a telecommunication network. It is made up of several layers and each layer provides services to the layer above.
15) What is TCP/IP?
TCP/IP stands for Transmission Control Protocol or Internet protocol.  It is used to connect hosts on the internet, by transferring data over the network.
16) What are RJ45 and RJ11 connectors?
RJ45 connectors are used for LAN/internet connections while RJ11 connectors are used for Table cable connectors.
17) What do you mean by packaging a Microprocessor? What are the different packaging’s available?
The process of packaging a microprocessor to the computer motherboard is known as a microprocessor.  The different types of microprocessor’s packaging are

• PGA
• SPGA
• SECC
• LGA

18) Explain the Cache memory? What is the advantage of a processor having more cache memory?
Cache memory is the memory area between Processor and Ram.  If the cache memory increases, the speed of the system will also increases.
19) What is over clocking? What are the advantages of over clocking?
It is a process where the computer component is forced to run at a higher clock rate.
The advantages of over clocking are:

• Increases the CPU’s performance
• It is cost-saving
• Makes PC games and Applications to run faster

20) What is chipset? How is it different from processor and motherboard?
 Chipset is one of the processing devices in a computer. It is a number of integrated circuits, designed to control how information travels between other components and processor. It is a group of microchip to work as a unit to perform one or more related functions. While motherboard is where all other components like CPU, Memory, Sockets for external connectors and drives are attached.  Chipset is a built in feature of Motherboard. While, processor is a main integrated circuit block, which does the function according to the instruction of a computer program.  It is based on the logical, arithmetical and input/output of the system.
21) What is heat sink and what is the use in the system?
To lower the temperature of a device, a heat sink component is used. It is there on the microprocessor and if it is not functioning well then the computer will shut down automatically.
22) What is Jumper and why you need it?
Jumper is a metal bridge that closes an electric circuit. A jumper consists of a plastic plug that fits over a pair of protruding pins.  It is used to change the board’s parameters.
23) What are the different types of DRAM?
The different types of DRAM are SRAM, VRAM, SGRAM, DDR-SDRAM
24) What might be the problem when you don’t see the display?

• Power related issues
• Heat sink related issues
• CPU fan related issues
• Improper Jumper settings

25) What is SATA?
SATA stands for Serial Advanced Technology Attachment.  It is high speed computer bus interface designed to connect the host bus adapters to mass storage devices, such as hard disk drives and optical drives.

Top 17 Active Directory Interview Questions & Answers

1) Mention what is Active Directory?
An active directory is a directory structure used on Microsoft Windows based servers and computers to store data and information about networks and domains.
2) Mention what are the new features in Active Directory (AD) of Windows server 2012?

• dcpromo (Domain Controller Promoter) with improved wizard: It allows you to view all the steps and review the detailed results during the installation process
• Enhanced Administrative Center: Compared to the earlier version of active directory, the administrative center is well designed in Windows 2012. The exchange management console is well designed
• Recycle bin goes GUI: In windows server 12, there are now many ways to enable the active directory recycle bin through the GUI in the Active Directory Administrative Center, which was not possible with the earlier version
• Fine grained password policies (FGPP): In windows server 12 implementing FGPP is much easier compared to an earlier  It allows you to create different password policies in the same domain
• Windows Power Shell History Viewer: You can view the Windows PowerShell commands that relates to the actions you execute in the Active Directory Administrative Center UI

3) Mention which is the default protocol used in directory services?
The default protocol used in directory services is LDAP ( Lightweight Directory Access Protocol).
4) Explain the term FOREST in AD?
Forest is used to define an assembly of AD domains that share a single schema for the AD.  All DC’s in the forest share this schema and is replicated in a hierarchical fashion among them.
5) Explain what is SYSVOL?
The SysVOL folder keeps the server’s copy of the domain’s public files.  The contents such as users, group policy, etc. of the sysvol folders are replicated to all domain controllers in the domain.

6) Mention what is the difference between domain admin groups and enterprise admins group in AD?

Enterprise Admin Group	Domain Admin Group
Members of this group have complete control of all domains in the forest By default, this group belongs to the administrators group on all domain controllers in the forest As such this group has full control of the forest, add users with caution	Members of this group have complete control of the domain By default, this group is a member of the administrators group on all domain controllers, workstations and member servers at the time they are linked to the domain As such the group has full control in the domain, add users with caution

7) Mention what system state data contains?
System state data contains

• Contains startup files
• Registry
• Com + Registration Database
• Memory page file
• System files
• AD information
• SYSVOL Folder
• Cluster service information

8) Mention what is Kerberos?
Kerberos is an authentication protocol for network.  It is built to offer strong authentication for server/client applications by using secret-key cryptography.

9) Explain where does the AD database is held? What other folders are related to AD?

AD database is saved in %systemroot%/ntds. In the same folder, you can also see other files; these are the main files controlling the AD structures they are

• dit
• log
• res 1.log
• log
• chk

10) Mention what is PDC emulator and how would one know whether PDC emulator is working or not?
PDC Emulators: There is one PDC emulator per domain, and when there is a failed authentication attempt, it is forwarded to PDC emulator.  It acts as a “tie-breaker” and it controls the time sync across the domain.
These are the parameters through which we can know whether PDC emulator is working or not.

• Time is not syncing
• User’s accounts are not locked out
• Windows NT BDCs are not getting updates
• If pre-windows 2000 computers are unable to change their passwords

11) Mention what are lingering objects?
Lingering objects can exists if a domain controller does not replicate for an interval of time that is longer than the tombstone lifetime (TSL).
12) Mention what is TOMBSTONE lifetime?
Tombstone lifetime in an Active Directory determines how long a deleted object is retained in Active Directory.  The deleted objects in Active Directory is stored in a special object referred as TOMBSTONE.  Usually, windows will use a 60- day tombstone lifetime if time is not set in the forest configuration.
13) Explain what is Active Directory Schema?
Schema is an active directory component describes all the attributes and objects that the directory service uses to store data.
14) Explain what is a child DC?
CDC or child DC is a sub domain controller under root domain controller which share name space
15) Explain what is RID Master?
RID master stands for Relative Identifier for assigning unique IDs to the object created in AD.
16) Mention what are the components of AD?
Components of AD includes

• Logical Structure: Trees, Forest, Domains and OU
• Physical Structures: Domain controller and Sites

17) Explain what is Infrastructure Master?
Infrastructure Master is accountable for updating information about the user and group and global catalogue.

Top 50 Desktop Support Interview Questions & Answers

1) What is active directory?
Active directory authorizes and authenticates all users and computers in a window domain network, ensuring the security of the computer and software. Through active directory various functions can be managed like creating admin users, connecting to printers or external hard drives.
2) What is DHCP and what it is used for?
DHCP stands for dynamic host configuration protocol. It is used to allocate IP addresses to a large number of the computer system in a network.  It helps in managing the large number of IP’s very easily.
3) What is scope and super scope?
Scope consists of an IP address like gateway IP, subnet mask, DNS server IP. It can be used to communicate with the other PCs in the network. The superscope becomes when you combine two or more scopes together.
4) What is DNS?
DNS mean Domain Naming Service and it is used for resolving IP addresses to name and names to IP address. DNS is like a translator for computers, computers understand the number and not the alphabet. For example, if we type like hotmail.com, the computer don’t understand this so they use DNS which converts (hotmail.com) into (numbers) and then executes the command.
5) What is forward and reverse lookup in DNS?
When we convert IP address into names is called Reverse lookup, while converting names into IP address is called Forward lookup.

Desktop Support

6) What is ‘A’ record and what is ‘MX record’?
‘A’ record is also known as host record, and it has ability to map the IP address by name. It is with this record that DNS can find out the IP address of a name. While, ‘MX record’ also known as mail exchanger record, by the help of ‘MX’ record, location of the mail server is identified.  The record is also found in DNS.
7) What is IPCONFIG command?
IPCONFIG command is used to display the IP information of the computer assigned like DNS IP address and gateway IP address.
8) What would you use to connect two computers without using switches?

Cross cables are used to connect two computers without using switches.
9) What is a domain?
Domain is a set of computers which network recognizes by the internet. It can be used by centrally administer computers. It is created when you install active directory.
10) Tell me if your system is infected by a virus how you will recover the data?
You need to re-install another system, latest anti-virus software and an O.S with latest patches.  Before you start your system, connect the infected HDD as a secondary drive then scan and clean the infected hard drive. Once done, you can copy the files into the system.
11) What is the operating system?
Operating system acts as an interpreter between computer application and hardware.  It works as an user interface.

12) What are the types of operating system or O.S?
The two types of operating systems are:

• NOS : Network Operating System. Examples of NOS- Windows NT, 2000,2003
• SOS : Simple Operating System. Examples of SOS – Windows 95,98, ME

13) Explain about RAS server?
RAS means Remote Access Server.  It allows operating the tool or information that typically resides on a network or IT devices through combination of hardware and software, for example connecting to printer or file. It is usually used for mobile users who are in the network. It uses telephone line to provide connectivity to its users. It can also connect two or more than two offices in the network.
14) Explain about VPN server?
VPN means Virtual Private Network. It is a private communications network often used by companies or organizations to communicate confidentially over a public network.  This is used by the mobile users in the network.
15) What is the difference between RAS and VPN server?
RAS is truly a local area connection between two connections whereas, VPN is a local connection spread over large area.
16)  What is IAS server?
IAS means Internet Authentication Service. For many types of network access like wireless, authenticating switch and remote access dial-up they perform accounting and auditing, centralized connection authentication and authorization.
17) What is Ping command?
Between two or more devices, to check the physical IP connectivity Ping command is used.
18) What do you mean by clustering? What are the benefits?
When one or more computers work together as a single system by sharing their resources is known as clustering.  The benefits of clustering are that it reduces the load on one single system by sharing the load also it is used for redundancy of the services.
19) What is a group?
Group is a collection of the user account. It provides the simplified administration in the network.
20) What is a child domain?
A child domain is the member domain of Windows 2000 Active Directory.
21) What are the benefits of a child domain?
Benefits of child domain are:

• Low network traffic
• Low administrative overhead
• Security boundary

22) What is OU?
OU means for Organizational Unit. It is a container within Active Directory which can hold users, groups and computers.  It is the smallest unit on which administrator can assign group policy settings.
23) Explain group policy?
Group policy provides the stream line access to all the users in the network, it can be used to define the users security and networking policies.  By group policy you can keep control over certain function like not allowing the users to shut down the system or using the control panel or running the command. Group policy is applicable on active directory container like OU, site and Domain.
24) What is the difference between permission, rights and policy?
“Policy” is assigned on active directory, like site, domain and OU. The “Rights” are assign to users and groups, whereas, the “Permission” is assigned for network resources like file, folders and printers.
25) What is DC and ADC stands for?
DC stands for domain controller and ADC stands for additional domain controller.
ADC is a backup of domain controller. Domain controller is a server that checks the security measures like user id, password.
26) What is the difference between DC (Domain controller) and ADC ( Additional Domain Controller)?
There is one difference between domain controller and additional domain controller, on DC all five operational roles are available while in ADC only three operational role is available.
27) What are the operational roles for DC (Domain controller) and ADC ( Additional Domain Controller)?
Operational roles for DC (Domain controller) are:

• Domain Naming Master
• Schema Master
• RID Master
• PDC Emulator
• Infrastructure Master

Operational roles for ADC (Additional Domain Controller) are:

• PDC Emulator
• RID Master
• Infrastructure Master

28) What is a “Default Gateway”?
Default gateway is the IP address of the router in the network.  In any case, if the users wants to switch on to another network, or if they cannot locate their particular network than their query will be forwarded to default gateway.
29) How you can take backup of emails in ms outlook?
To take a back-up in the ms outlook, you have to go in control panel. In control panel you have to go under mail option and then open the data file, select personal folder and click on open folder. After that, you have to copy .pst and have to paste it wherever you want the backup.
30) What is trusting domain and trusted domain?
In trusting domain resources are available, while in trusted domain user’s account is available.
31) What is BUS speed?
The rate of communication speed between microprocessor and RAM is known as BUS speed.
32) Name the Active Directory Partitions?
There are three types of active directory partitions

• Schema partition
• Configuration partition
• Domain partition

33) What is Fixboot?
Fixboot write a new partition boot sector on to the system partition.
34) How many logical drive is it possible to fit on to a physical disk?
The maximum number of the logical drive that can fit on a physical disk is 24, while the extended partition can only have 23 logical drives.
35) What is B Router?
B router means Bridge router. To provide communication between two or more different network like computer to computer or computer to internet, B Router is used.
36) What is the major difference you can mention about Gateway and Router?
Gateway works on different network architecture and router works on same network architecture.
37) What is packet?
A packet is a logical grouping of information that comprises a header which contains user data and location information.
38) What is SCSI?
SCSI stands for Small Computer System Interface. It is a standard electronic interface that allows personal computers to communicate with peripheral hardware such as disk drives, tape drives, printers, CD-ROM drives. In “SCSI” the rate of data transmission is fast.
39) How many classes are there for “IP addresses” and what are the ranges?
They are segregated into five classes

1. Class A  ===          0 -126 ( 127 is reserved for loop back)
2. Class B  ====    128- 191
3. Class C  ====    192-223
4. Class D  ====   224-239
5. Class E  ====   240-255

40) Explain the term FIXMBR?
FIXMBR it is a repair tool. It repairs the Master boot record of the Partition Boot Sector.
41) Explain the term SID?
SID stands for Security Identifier. Every computer object has a unique ID which is known as SID.
42) What is the difference between incremental backup and differential backup?
Differential backups will select only files that are changed since the last backup.
Incremental backups will select only the data that has changed since the last backup.
Example, On Sunday you do a backup of a 5 text file each of 40 MB. Total backup size will be 200MB
On Monday you change 2 lines in just ONE of the text file.
Under Differential backup, only the changed text file will be backed up. Total backup size will be 40MB
Under Incremental backup, only the data corresponding to the 2 lines will be backed up.  Total backup size will be just in bytes.
43) What is the difference between server OS and desktop OS?
Server OS gives centralized administration for users, shared resources and security while desktop OS gives access to only local administration.
44) What is the difference between the MSI file and .EXE file?
MSI (Microsoft Installer) allows install, uninstall and repair the program with a single file, while .EXE file needs two files to install and uninstall the software. Also,.EXE file is able to detect the existing version of the software and give option to user to uninstall the program while MSI will instruct the users to use the add and remove program in control panel to remove the existing product first and then you can install the new program.
45) What is BSOD? How do you troubleshoot it?
BSOD stands for blue screen of death. When there is some fault in OS or hardware then Windows can’t run the program and gives a blue screen with a code. To resolve this problem the best way is to reboot the system.  If it doesn’t work than boot the system in the safe mode.
46) What is PTR (Program Troube Record) record?
This program record is used to check if the server name is connected with the IP address, it is exactly opposite to the ‘A’ record. This record is basically created in reverse lookup zone, so it is also known as Reverse DNS records or pointer record.
PTR record= Give me an IP address and I will give you the name
‘A’ record= Give me the name and I will give you the IP address
47)  What is reservation?
Basically the term “Reservation” is used in DHCP server. Some network equipment or computer system needs a specific IP address, in such case we make a reservation in DHCP server for that particular computer system.  By creating reservation it gives access to that particular IP address and at the same time prevents other computer system to use that IP address.
48) What is SMTP server or POP server?
SMTP stands for simple mail transfer protocol. It is basically used for sending and receiving the mail, whereas, POP stands for post office protocol it is used for mail receiving purpose in the network.
49) What is RIS and why you use RIS?
RIS stands for remote installation services. It is used to install image from a Window server to a new hardware.  We use RIS because installing OS every time using a CD would be more time consuming.
50) What is “Bootloader”?
Bootloader facilitates the loading of operating system on the system. It enables the booting process and gives OS option to the users while starting the system.

Top 50 Networking Interview Questions & Answers 2

51) What protocol can be applied when you want to transfer files between different platforms, such between UNIX systems and Windows servers?
Use FTP (File Transfer Protocol) for file transfers between such different servers. This is possible because FTP is platform independent.
52) What is the use of a default gateway?
Default gateways provide means for the local networks to connect to the external network. The default gateway for connecting to the external network is usually the address of the external router port.
53) One way of securing a network is through the use of passwords. What can be considered as good passwords?
Good passwords are made up of not just letters, but by combining letters and numbers. A password that combines uppercase and lowercase letters is favorable than one that uses all upper case or all lower case letters. Passwords must be not words that can easily be guessed by hackers, such as dates, names, favorites, etc. Longer passwords are also better than short ones.
54) What is the proper termination rate for UTP cables?
The proper termination for unshielded twisted pair network cable is 100 ohms.
55) What is netstat?
Netstat is a command line utility program. It provides useful information about the current TCP/IP settings of a connection.
56) What is the number of network IDs in a Class C network?
For a Class C network, the number of usable Network ID bits is 21. The number of possible network IDs is 2 raised to 21 or 2,097,152. The number of host IDs per network ID is 2 raised to 8 minus 2, or 254.
57) What happens when you use cables longer than the prescribed length?
Cables that are too long would result in signal loss. This means that data transmission and reception would be affected, because the signal degrades over length.
58) What common software problems can lead to network defects?
Software related problems can be any or a combination of the following:
– client server problems
– application conflicts
– error in configuration
– protocol mismatch
– security issues
– user policy and rights issues
59) What is ICMP?
ICMP is Internet Control Message Protocol. It provides messaging and communication for protocols within the TCP/IP stack. This is also the protocol that manages error messages that are used by network tools such as PING.
60) What is Ping?
Ping is a utility program that allows you to check connectivity between network devices on the network. You can ping a device by using its IP address or device name, such as a computer name.
61) What is peer to peer?
Peer to peer are networks that does not reply on a server. All PCs on this network act as individual workstations.
62) What is DNS?
DNS is Domain Name System. The main function of this network service is to provide host names to TCP/IP address resolution.
63) What advantages does fiber optics have over other media?
One major advantage of fiber optics is that is it less susceptible to electrical interference. It also supports higher bandwidth, meaning more data can be transmitted and received. Signal degrading is also very minimal over long distances.
64) What is the difference between a hub and a switch?
A hub acts as a multiport repeater. However, as more and more devices connect to it, it would not be able to efficiently manage the volume of traffic that passes through it. A switch provides a better alternative that can improve the performance especially when high traffic volume is expected across all ports.
65) What are the different network protocols that are supported by Windows RRAS services?
There are three main network protocols supported: NetBEUI, TCP/IP, and IPX.
66) What are the maximum networks and hosts in a class A, B and C network?
For Class A, there are 126 possible networks and 16,777,214 hosts
For Class B, there are 16,384 possible networks and 65,534 hosts
For Class C, there are 2,097,152 possible networks and 254 hosts
67) What is the standard color sequence of a straight-through cable?
orange/white, orange, green/white, blue, blue/white, green, brown/white, brown.
68) What protocols fall under the Application layer of the TCP/IP stack?
The following are the protocols under TCP/IP Application layer: FTP, TFTP, Telnet and SMTP.
69) You need to connect two computers for file sharing. Is it possible to do this without using a hub or router?
Yes, you can connect two computers together using only one cable. A crossover type cable can be use in this scenario. In this setup, the data transmit pin of one cable is connected to the data receive pin of the other cable, and vice versa.
70) What is ipconfig?
Ipconfig is a utility program that is commonly used to identify the addresses information of a computer on a network. It can show the physical address as well as the IP address.
71) What is the difference between a straight-through and crossover cable?
A straight-through cable is used to connect computers to a switch, hub or router. A crossover cable is used to connect two similar devices together, such as a PC to PC or Hub to hub.
72) What is client/server?
Client/server is a type of network wherein one or more computers act as servers. Servers provide a centralized repository of resources such as printers and files. Clients refers to workstation that access the server.
73) Describe networking.
Networking refers to the inter connection between computers and peripherals for data communication. Networking can be done using wired cabling or through wireless link.
74) When you move the NIC cards from one PC to another PC, does the MAC address gets transferred as well?
Yes, that’s because MAC addresses are hard-wired into the NIC circuitry, not the PC. This also means that a PC can have a different MAC address when the NIC card was replace by another one.
75) Explain clustering support
Clustering support refers to the ability of a network operating system to connect multiple servers in a fault-tolerant group. The main purpose of this is the in the event that one server fails, all processing will continue on with the next server in the cluster.
76) In a network that contains two servers and twenty workstations, where is the best place to install an Anti-virus program?
An anti-virus program must be installed on all servers and workstations to ensure protection. That’s because individual users can access any workstation and introduce a computer virus when plugging in their removable hard drives or flash drives.
77) Describe Ethernet.
Ethernet is one of the popular networking technologies used these days. It was developed during the early 1970s and is based on specifications as stated in the IEEE. Ethernet is used in local area networks.
78) What are some drawbacks of implementing a ring topology?
In case one workstation on the network suffers a malfunction, it can bring down the entire network. Another drawback is that when there are adjustments and reconfigurations needed to be performed on a particular part of the network, the entire network has to be temporarily brought down as well.
79) What is the difference between CSMA/CD and CSMA/CA?
CSMA/CD, or Collision Detect, retransmits data frames whenever a collision occurred. CSMA/CA, or Collision Avoidance, will first broadcast intent to send prior to data transmission.
80) What is SMTP?
SMTP is short for Simple Mail Transfer Protocol. This protocol deals with all Internal mail, and provides the necessary mail delivery services on the TCP/IP protocol stack.
81) What is multicast routing?
Multicast routing is a targeted form of broadcasting that sends message to a selected group of user, instead of sending it to all users on a subnet.
82) What is the importance of Encryption on a network?
Encryption is the process of translating information into a code that is unreadable by the user. It is then translated back or decrypted back to its normal readable format using a secret key or password. Encryption help ensure that information that is intercepted halfway would remain unreadable because the user has to have the correct password or key for it.
83) How are IP addresses arranged and displayed?
IP addresses are displayed as a series of four decimal numbers that are separated by period or dots. Another term for this arrangement is the dotted decimal format. An example is 192.168.101.2
84) Explain the importance of authentication.
Authentication is the process of verifying a user’s credentials before he can log into the network. It is normally performed using a username and password. This provides a secure means of limiting the access from unwanted intruders on the network.
85) What do mean by tunnel mode?
This is a mode of data exchange wherein two communicating computers do not use IPSec themselves. Instead, the gateway that is connecting their LANs to the transit network creates a virtual tunnel that uses the IPSec protocol to secure all communication that passes through it.
86) What are the different technologies involved in establishing WAN links?
Analog connections – using conventional telephone lines; Digital connections – using digital-grade telephone lines; switched connections – using multiple sets of links between sender and receiver to move data.
87) What is one advantage of mesh topology?
In the event that one link fails, there will always be another available. Mesh topology is actually one of the most fault-tolerant network topology.
88) When troubleshooting computer network problems, what common hardware-related problems can occur?
A large percentage of a network is made up of hardware. Problems in these areas can range from malfunctioning hard drives, broken NICs and even hardware startups. Incorrectly hardware configuration is also one of those culprits to look into.
89) What can be done to fix signal attenuation problems?
A common way of dealing with such a problem is to use repeaters and hub, because it will help regenerate the signal and therefore prevent signal loss. Checking if cables are properly terminated is also a must.
90) How does dynamic host configuration protocol aid in network administration?
Instead of having to visit each client computer to configure a static IP address, the network administrator can apply dynamic host configuration protocol to create a pool of IP addresses known as scopes that can be dynamically assigned to clients.
91) Explain profile in terms of networking concept?
Profiles are the configuration settings made for each user. A profile may be created that puts a user in a group, for example.
92) What is sneakernet?
Sneakernet is believed to be the earliest form of networking wherein data is physically transported using removable media, such as disk, tapes.
93) What is the role of IEEE in computer networking?
IEEE, or the Institute of Electrical and Electronics Engineers, is an organization composed of engineers that issues and manages standards for electrical and electronic devices. This includes networking devices, network interfaces, cablings and connectors.
94) What protocols fall under the TCP/IP Internet Layer?
There are 4 protocols that are being managed by this layer. These are ICMP, IGMP, IP and ARP.
95) When it comes to networking, what are rights?
Rights refer to the authorized permission to perform specific actions on the network. Each user on the network can be assigned individual rights, depending on what must be allowed for that user.
96) What is one basic requirement for establishing VLANs?
A VLAN is required because at switch level there is only one broadcast domain, it means whenever new user is connected to switch this information is spread throughout the network. VLAN on switch helps to create separate broadcast domain at  switch level. It is used for security purpose.
97) What is IPv6?
IPv6 , or Internet Protocol version 6, was developed to replace IPv4. At present, IPv4 is being used to control internet traffic, butis expected to get saturated in the near future. IPv6 was designed to overcome this limitation.
98) What is RSA algorithm?
RSA is short for Rivest-Shamir-Adleman algorithm. It is the most commonly used public key encryption algorithm in use today.
99) What is mesh topology?
Mesh topology is a setup wherein each device is connected directly to every other device on the network. Consequently, it requires that each device have at least two network connections.
100) what is the maximum segment length of a 100Base-FX network?
The maximum allowable length for a network segment using 100Base-FX is 412 meters. The maximum length for the entire network is 5 kilometers.