Question 1

Consider a computer with a 4 MHz processor. Its DMA controller can transfer 8 bytes in 1 cycle from a device to main memory through cycle stealing at regular intervals. What is the data transfer rate (in bits per second) of the DMA controller if 1% of the processor cycles are used for DMA?

Accepted Answer

25,60,000. The DMA controller transfers 8 bytes per cycle, and with a 4 MHz processor, it has 4 million cycles per second. Since only 1% of the cycles are used for DMA, the effective cycles for data transfer are 40,000 per second. Thus, the total data transferred per second is 40,000 cycles multiplied by 8 bytes, which equals 320,000 bytes or 2,560,000 bits.

Question 2

Let p and q be the following propositions:
p: Fail grade can be given.
q: Student scores more than 50% marks.
Consider the statement: “Fail grade cannot be given when student scores more than 50% marks.”
Which one of the following is the CORRECT representation of the above statement in pro

Accepted Answer

q → ¬ p. The statement indicates that if a student scores more than 50% marks (q), then a fail grade cannot be given (¬p). This is correctly represented by the implication q → ¬p, meaning that a high score guarantees that a fail grade is not possible.

Question 3

Consider a single processor system with four processes A, B, C, and D, represented as given below, where for each process the first value is its arrival time, and the second value is its CPU burst time. A (0, 10), B (2, 6), C (4, 3), and D (6, 7). Which one of the following options gives t

Accepted Answer

SRTF = 6, N-P-SJF = 7.5. The correct option indicates that under the preemptive SRTF scheduling, the average waiting time is minimized to 6 because processes are executed based on their remaining burst time, allowing shorter jobs to interrupt longer ones. In contrast, the non-preemptive SJF scheduling results in an average waiting time of 7.5, as processes are executed in the order of their burst times without preemption, leading to longer waiting times for some processes.

Question 4

Which one of the following CIDR prefixes exactly represents the range of IP addresses 10.1.2.2 to 10.1.2.255?

Accepted Answer

10.1.2.0/24. The CIDR prefix 10.1.2.0/24 encompasses all IP addresses from 10.1.2.0 to 10.1.2.255, which includes the range specified in the question. This prefix allows for 256 addresses, making it the exact match for the given range.

Question 5

You are given a set V of distinct integers. A binary search tree T is created by inserting all elements of V one by one, starting with an empty tree. The tree T follows the convention that, at each node, all values stored in the left subtree of the node are smaller than the value stored at

Accepted Answer

Inorder traversal of T can be determined from V. The inorder traversal of a binary search tree always results in the values being sorted in ascending order. Since the set V consists of distinct integers, the inorder traversal can be directly derived from the sorted version of V, regardless of the insertion order.

Question 6

Consider the following context-free grammar where the start symbol is S and the set of terminals is {a,b,c,d}.

S → AaAb | BbBa
A → cS | ε
B → dS | ε

The following is a partially-filled LL(1) parsing table.

Columns: a, b, c, d,
Rows:
S: (a) S → AaAb, (b) S → BbBa, (c) (1), (d) (2), () bl

Accepted Answer

(1) S → AaAb (2) S → BbBa (3) A → ε (4) B → ε. The correct option is right because it accurately fills the LL(1) parsing table based on the productions of the grammar. For the non-terminal S, the first production is chosen for 'a' and the second for 'b', while A can derive ε for 'a' and B can also derive ε for 'b', aligning with the grammar's rules.

Question 7

Consider an array X that contains n positive integers. A subarray of X is defined to be a sequence of array locations with consecutive indices.

The C code snippet given below has been written to compute the length of the longest subarray of X that contains at most two distinct integers. T

Accepted Answer

1; len1+1. The correct expressions are '1' for (P) because it resets the count of the new distinct integer, and 'len1+1' for (Q) because it adds the length of the previous longest subarray of the first distinct integer to the current count, effectively extending the subarray to include the new distinct integer.

GATE Technical: Computer Science and Information Technology Set 2 (CS2) questions with solutions

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