Common Interview Questions.
- Name the components of CPU
Ans. ALU, PC, Accumulator, MAR, IR, ID, MDR
- What is the use of registers in CPU?
Ans. It is used to store intermediate data and instructions.
- What is the function of MAR?
Ans. It specifies the address of memory location from which data or instruction is to be accessed or to which the data is to be stored.
- What is the function of MDR / MBR?
Ans. It contains the data to be written into or read from memory location addressed by MAR.
- What is program counter?
Ans. It keeps track of the memory address of the instruction that is to be executed next.
- What is the function of IR?
Ans. It contains the instruction that is being executed.
- What is the purpose of Instruction Decoder?
Ans. It decodes the instructions.
- What is a data bus?
Ans. It carries a word to or from memory.
- What is an address bus?
Ans. It carries memory address. The width of address bus equals the number of bits in the MAR.
- What is the function of control bus?
Ans. It carries signals between the units of the computer.
- Name different I/O ports.
Ans. Port is a socket on the back of computer. Different types of ports are serial ports, parallel ports and USB ports.
- What is meant by plug and play cards?
Ans. It enables the user to add devices to computer.
- Expand SD RAM.
Ans. Synchronous Dynamic Random Access Memory.
- Expand DDR RAM
Ans. Double Data Rate Random Access Memory.
- Explain USB Port (Universal Serial Bus).
Ans. a. It is a high speed serial bus
b. It is a plug and play interface between computers and add on devices.
- Give the specifications of Laser printer.
Ans. a. Resolution varies from 600 to 1200 dots per inch.
b. Speed varies from 4 PPM to 24 PPM.
c. Buffer size varies from 4MB to 32 MB
d. Can print color images.
- Give the specifications of dot matrix printer.
Ans. a. Print head normally has 9 pins to 24 pins.
b. Speed varies from 30 to 300 characters per second.
c. Buffer size varies from 1K to 64 K.
- Give the specifications of inkjet printer.
a. Resolution is around 300 dots per inch.
b. Speed varies from 1PPM to 12 PPM
c. Buffer size varies from 1 MB to 4 MB.
- Write a note on computer maintenance.
a. Avoid heat dust and noise
b. Periodic updates and enhancements
c. Installing fire walls and anti virus.
d. In house software maintenance
e. Computer periodic checkup.
- What are the possible threats to a computer system and how to provide security?
c. Environmental damage
d. Human threats
e. Software threats
f. Unauthorized access
g. Computer viruses
a. Physical protection of machine and media.
b. Giving passwords and users ID
c. Using Licensed software
d. Use of Cryptography
e. Use of Spike busters and UPS
- Explain the typical causes of computer failures.
a. Break down of components.
b. Excessive dust or humidity
d. Voltage fluctuation
- Write a note on Computer virus.
Ans: Viruses are collection of coded instructions which are self replicating. When a virus attaches itself to another file it infects it. They are normally inactive until infected program is run. They are broadly classified into three categories.
a. Boot infectors
b. System infectors
c. Executable program infectors
Boot infectors: Create bad sectors. They remain in the memory until the system is shutdown.
System infectors: It infects the hard disk or: bootable floppies which may contain system files.
Executable program infectors: These are dangerous and devastating. They spread to almost any executable program attaching themselves to programming files.
- Explain the cache memory in detail.
Ans: Cache memory is a small and fast memory between CPU and main memory. It is extremely fast compared to normal memory. Transferring data between main memory and CPU causes delay because RAM is slower than CPU. Cache memory stores copies of data from most frequently used main memory locations. When processor needs to read from or write to a location in main memory, it first checks whether a copy of data is in the cache. If so processor immediately reads or writes to cache. Computers use multilevels of cache such as Level1(smallest)and Level2 cache.CPU resident cache is known as L1 or primary cache (16 to 32 KB) to 512 KB.Cache is also added to mother board also known as L2 cache (512 KB to 1024 KB). Higher end systems can have as much as 2 MB of L2 cache on mother board.