A Level Computer Science OCR Practice Exam

What is the primary function of a queue in computing?

1. To store a last-in first-out collection

2. To hold the instructions to execute in order

3. To manage memory allocation

4. To perform mathematical calculations

The correct answer is: To hold the instructions to execute in order

The primary function of a queue in computing is to hold entities in a first-in first-out (FIFO) manner, which means that the first element added to the queue will be the first one to be removed. This characteristic makes queues particularly useful for managing tasks or processes in a specific order, such as scheduling instructions that need to be executed sequentially. In this context, the choice that highlights this aspect of queues is the one that indicates their role in holding instructions to execute in a particular order. When tasks are added to a queue, they are processed in the order they arrive, which is critical in scenarios like print spooling, process scheduling in operating systems, or handling requests in web servers. This orderly processing ensures that resources are utilized efficiently and that tasks are carried out without missing any step. The other options do not accurately reflect the primary function of a queue. For example, the first option describes a stack’s function (last-in first-out), and while memory management pertains to resources utilized during program execution, it is not the defining role of a queue. Lastly, the option regarding mathematical calculations does not relate to the fundamental purpose of a queue, which is more about managing data and tasks rather than performing computations.