List two disadvantges of a database system as compared to a file-based system.

Database systems are complex, difficult and time consuming.
Damage to data base affects virtually all application programs.

List the basic difference between DOS and UNIX.

DOS is a single user operating system and UNIX is multiuser operating system.

What is ARP ? How it differ from IP?

ARP: Address Resolution Protocol is a computer networking protocol for determining a network host's hardware address when only its logical address is given. This hardware address is required to transfer data from one node to another.

IP: Internet Protocol is the primary protocol in the internet layer of internet protocol suite. It is used for delivering datagrams from the source host to the destination host solely based on their logical addresses.

In OSI protocol suite ARP comes in data link layer and IP is in network layer.

Is a two dimensional array passed as a value or reference argument to a function ?

Two dimensional arrays are passed as reference argument. If a two dimensional array is to be passed to a function, the parameter declaration in the function must include the number of columns. The number of rows is irrelevant since what is passed is a pointer to an array to rows.

What is a foreign key in an RDBMS?

A foreign key in a relation is an attribute which is primary key of some other relation.

Mention two advantages of a DBMS over a file storage of data.

Data redundary can be avoided by using DBMS.
DBMS provide backup and recovery and concurrency control.

Between the iterative routine sum-iter and recursive routine sum-rec, which is more efficient and why?

Sum-iter function is more efficient than the recursive function sum-rec. Ever time a recursive function calls itself all the local variables are saved in a stack. At the time of returning the values stored in stack are poped out. Thus recursive functions consume more memory space and time.

A Relational operator ?

Yields of a Boolean result

A static variable is one ?

Which retains its value throughout the life of the program.

How is XCOPY a better command than COPY ?

XCOPY command copy the whole directory, sub folders and all files within it. It also copies all hidden files.

COPY command only copies the files mentioned as arguments in the command XCOPY is much powerful than COPY command.

Distinguish berween break and continue statements in C.

A break statement terminates the execution of the loop and the control is transferred to the statement immediately following the loop.

Continue statement is used to bypass the remainder of the current pass through a loop.

What is the difference between process and processor ?

Process is a program under execution. It include the program executed, associated data and stack space.

Processor is the hardware that executes the program. It is the CPU of computer.

Distinguish between the block variable and the local variable?

A block variable is valid only within the block in which it is defined.  It is not visible outside the block.  It is created when program control enters the block and is destroyed when program control exits the block.

A local variable is visible throughout the function in which it is defined.

What is Bitwise Operator?

A bitwise operator operates on each bit of data. These operators are used for testing,  complementing and shifting bits to the right or left.