10 PYQ questions related to Queue

 MCQ questions related to Queue with descriptions for UGC NET, SET, GATE AND ASSISTANT PROFESSOR etc..

1. GATE CS 2019
   Which of the following data structures is best suited for Breadth-First Search (BFS)?
   A) Stack
   B) Queue
   C) Priority Queue
   D) Linked List
   Answer: B) Queue
   Description: BFS explores neighbors level by level. A queue efficiently supports this by enqueuing and dequeuing nodes in the order they are discovered.

2. UGC NET 2020
   Which type of queue allows insertion and deletion from both ends?
   A) Simple Queue
   B) Circular Queue
   C) Double-Ended Queue (Deque)
   D) Priority Queue
   Answer: C) Double-Ended Queue (Deque)
   Description: A deque (double-ended queue) supports insertion and deletion from both front and rear ends, making it versatile for various applications.

3. ISRO Scientist 2018
   What is the time complexity of the enqueue() and dequeue() operations in a queue implemented using a linked list?
   A) O(1)
   B) O(n)
   C) O(log n)
   D) O(n²)
   Answer: A) O(1)
   Description: In a linked list-based queue, both enqueue (insert at the rear) and dequeue (remove from the front) operations take constant time.

4. NIELIT Scientist B 2019
   Which of the following queue types is used for job scheduling in operating systems?
   A) Circular Queue
   B) Priority Queue
   C) Simple Queue
   D) Deque
   Answer: B) Priority Queue
   Description: Priority queues manage processes with different priorities, ensuring that higher-priority tasks are executed first.

5. GATE CS 2018
   What happens when you try to dequeue an element from an empty queue?
   A) Underflow
   B) Overflow
   C) Segmentation Fault
   D) None of the above
   Answer: A) Underflow
   Description: Queue underflow occurs when a dequeue operation is performed on an empty queue, indicating that no elements are available to remove.

6. UGC NET 2017
   Which of the following is NOT a queue operation?
   A) Enqueue
   B) Dequeue
   C) Peek
   D) Push
   Answer: D) Push
   Description: The push() operation is specific to stacks, while enqueue(), dequeue(), and peek() are queue operations.

7. GATE CS 2016
   What is the primary disadvantage of a simple queue?
   A) Fixed size
   B) Underflow
   C) Wastage of space
   D) Complexity
   Answer: C) Wastage of space
   Description: In a simple queue implemented using an array, when elements are dequeued from the front, vacant spaces are not reused, leading to wastage.

8. NIELIT Scientist B 2018
   Which of the following applications uses a circular queue?
   A) Printer Spooling
   B) Function Call Management
   C) Undo Operations
   D) Recursion Handling
   Answer: A) Printer Spooling
   Description: Circular queues are used in printer spooling to manage ongoing print jobs efficiently without wasting space.

9. GATE CS 2020
   Which queue operation is used to retrieve the element at the front without removing it?
   A) Enqueue
   B) Dequeue
   C) Peek
   D) Front
   Answer: C) Peek
   Description: The peek() operation returns the element at the front of the queue without deleting it, helping in checking the front element.

10. UGC NET 2021
    Which of the following queues automatically removes elements based on priority rather than order of arrival?
    A) Simple Queue
    B) Circular Queue
    C) Priority Queue
    D) Deque
    Answer: C) Priority Queue
    Description: A priority queue removes the highest-priority element first, unlike simple queues that follow the First In, First Out (FIFO) principle.