GATE-CS-2016 (Set 2)

Question 61

Consider a 128×10³ bits/second satellite communication link with one-way propagation delay of 150 milliseconds. Selective retransmission (repeat) protocol is used on this link to send data with a frame size of 1 kilobyte. Neglect the transmission time of acknowledgment. The minimum number of bits required for the sequence number field to achieve 100% utilization is ___________

• 2
• 4
• 6
• 8

Question 62

The value printed by the following program is

C

void f(int* p, int m)
{
    m = m + 5;
    *p = *p + m;
    return;
}
void main()
{
    int i=5, j=10;
    f(&i, j);
    printf(\"%d\", i+j);
}

• 10
  

• 20
  

• 30
  

• 40
  

Question 63

B+ Trees are considered BALANCED because

• the lengths of the paths from the root to all leaf nodes are all equal.
• the lengths of the paths from the root to all leaf nodes differ from each other by at most 1.
• the number of children of any two non-leaf sibling nodes differ by at most 1.
• the number of records in any two leaf nodes differ by at most 1.

Question 64

The following function computes X^Y for positive integers X and Y.

C

int exp(int X, int Y)
{
    int res = 1, a = X, b = Y;
    while ( b != 0 )
    {
        if ( b%2 == 0)
        {
            a = a*a;
            b = b/2;
        }
        else
        {
            res = res*a;
            b = b-1;
        }
    }
    return res;
}

Which one of the following conditions is TRUE before every iteration of the loop

• A
• B
• C
• D

Question 65

Anarkali digitally signs a message and sends it to Salim. Verification of the signature by Salim requires

• Anarkali’s public key.
• Salim’s public key.
• Salim’s private key.
• Anarkali’s private key.