Difficult Question Paper Questions and Answers

Question 1

Describe what an embedded operating system is. [3]

Answer 1

-A computer system that is built within a larger mechanical system and is designed to perform a dedicated function [1]
-Low level operating system [1]
-Has simple/ no user interface [1]
-Optimised to reduce response times specifically for the task the device was created for [1]

Question 2

Explain why the hexadecimal number system is used and state an example of its use. [3]

Answer 2

-Hexadecimal is easier to read for humans [1]
-Hexadecimal uses fewer digits to represent a number than binary… [1]
-…therefore is less likely to have input errors [1]
Example of use:
-tTo represent MAC addresses [1]

Question 3

Explain how bitmap images are stored by a computer. [4]

Answer 3

-Image is made up of pixels [1]
-Each pixel is given a binary code [1]
-…which presents the colour of that pixel [1]
-metadata is stored with the image [1]

Question 4

Describe how an analogue sound wave is converted into digital form.

Answer 4

-(analogue) sound waves is sampled [1]
-..amplitude of wave is measured [1]
-…at regular time intervals [1]
-each sample is stored as a binary number [1]

Question 5

Compare the advantages and disadvantages of using virtual memory. [4]

Answer 5

-Virtual memory allows the user to run/have more applications
open concurrently[1]
-Virtual memory allows a device to operate as if it has more RAM than is physically installed[1]
-user does not have to buy more RAM[1]
-Takes time to swap files from virtual memory back into RAM[1]
-It can make applications run more slowly[1]

Question 6

It is better to install additional RAM to improve the performance of a computer instead of relying on virtual memory.
Explain the purpose of virtual memory and justify why this statement is correct. [6]

Answer 6

-Virtual memory uses secondary storage as if it were RAM[1]
-…to hold open more programs than physical RAM could hold open when RAM is FULL[1]
-instructions / data that is not currently being used is moved to virtual memory to make space in RAM[1]
-virtual memory can make the computer slower to respond when switching between applications[1]
-more RAM will speed up access to data[1]
-…leading to increased performance[1]