GATE 2012 Computer Science Questions With Solutions

1. An organization has a class B network and wishes to form subnets for 64 departments. The subnet mask would be

1. 255.255.0.0
2. 255.255.252.0
3. 255.255.128.0
4. 255.255.64.0

2. Let G be a simple graph with 20 vertices and 100 edges. The size of the minimum vertex cover of G is 8. Then, the size of the maximum independent set of G is

1. More than 12
2. Less than 8
3. 12
4. 8

3. The order of an internal node in a B+ tree index is the maximum number of children it can have. Suppose that a child pointer takes 6 bytes, the search field value takes 14 bytes, and the block size is 512 bytes. What is the order of the internal node?

1. 24
2. 26
3. 27
4. 25

4. The minimum number of page frames that must be allocated to a running process in a virtual memory environment is determined by

1. page size
2. physical memory size
3. the instruction set architecture
4. number of processes in memory

5. The best data structure to check whether an arithmetic expression has balanced parentheses is a

1. list
2. tree
3. stack
4. queue

6. Suppose the round trip propagation delay for a 10 Mbps Ethernet having 48-bit jamming signal is 46.4 ms. The minimum frame size is:

1. 464
2. 94
3. 416
4. 512

7. Consider the following C program
main ()
{
int x, y, m, n ;
scanf (“%d %d”, &x, &y); / * Assume x > 0 and y > 0 * /
m = x; n = y ;
while ( m ! = n)
{
if (m > n)
m = m + n;
else n = n – m ;
}
printf(“%d”,n);
}
The program computes

1. x mod y using repeated subtraction
2. the greatest common divisor of x and y
3. the least common multiple of x and y
4. x + y, using repeated subtraction

8. The minimum number of page frames that must be allocated to a running process in a virtual memory environment is determined by

1. the instruction set architecture
2. physical memory size
3. page size
4. number of processes in memory

9. Consider the following C function:
int f (int n)
{
static int i = 1;
if (n >= 5)
return n;
n = n + i;
i++;
return f (n);
}
The value returned by f(1) is

1. 5
2. 8
3. 6
4. 7

10. A Priority-Queue is implemented as a Max-Heap. Initially, it has 5 elements. The level-order traversal of the heap is given below: 10, 8,5,3,2 Two new elements 1 and 7 are inserted in the heap in that order. The level-order traversal of the heap after the insertion of the elements is

1. 10,8,7,3,2,1,5
2. 10,8,7,5,3,2,1
3. 10,8,7,1,2,3,5
4. 10,8,7,2,3,1,5

11. The following numbers are inserted into an empty binary search tree in the given order: 10, 1, 3, 5, 15, 12, 16. What is the height of the binary search tree (the height is the maximum distance of a leaf node from the root)?

1. 2
2. 4
3. 3
4. 6

12. The relation scheme Student Performance (name, courseNo, rollNo, grade) has the following functional dependencies:
The highest normal form of this relation scheme is:

1. name, courseNo -> grade
2. rollNo, courseNo -> grade
3. rollNo -> name
4. name -> rollNo

Support your answers with explanation.