PPE Exam Revision

Question 1

What is “text represented in a computer”?

Answer 1

A code where each number is represented as a character and can be used convert text into binary.

Question 2

Give inputs, outputs and storage for a mobile phone:

Answer 2

Inputs:

• Sensory touch screen
• Microphone
• Camera
• Keyboard

Output:

• Monitor/Screen
• Speakers

Storage:

• ROM and RAM
• hard disk

Question 3

What is meant by “off-the-shelf- software?

Answer 3

Software that is aimed at many users and sold “as is”.

Question 4

What is the data type for the following:
Gender?
Dose?

Answer 4

Gender is a string

Dose is a real number

Question 5

Security in a computer (give examples)

Answer 5

Security utilities:

• stronger passwords
• encryption
• anti-virus software

Operating system:

• manages cpu
• manages peripherals
• manages memory

Question 6

High level and machine code, explain the differences and which is better.

Answer 6

High level code is much more easier than machine code (Los level code). This is because low level code (machine code) can only be understood by the computer, not so much by the user. Additionally, high level language is portable and can be understood by the user, therefore easier and more efficient.

Question 7

Why is databases important/efficient?

Answer 7

• a large number of data can be stored efficiently
• data can be added easily/edited rapidly
• information can be found quicker

Question 8

What are the standards of coding?

Answer 8

• should be spaced out evenly
• functions are named appropriately
• variable names are consistent throughout

Question 9

What is the purpose of a CPU?

Answer 9

Control unit uses electrical signals to the system to execute instructions in stored programs.

Question 10

What is a RAM used for?

Answer 10

Where the program is stored.

Question 11

Why is cache memory used?

Answer 11

It it used to store data that is waiting to be processed.

Question 12

What is op code?

Answer 12

The big pattern for the operator, the part of a machine code instruction that defines the operation to be performed.

Question 13

Why is there LAN in a bank for school?

Answer 13

To protect personal information and passwords and encryptions.

Question 14

Explain IP addresses and MAC addresses and what they are written in.

Answer 14

IP addresses are usually written in denary and MAC is usually written in hex, both addresses are written as numbers. MAC addresses are coded in to the hardware during manufacture.

Question 15

What can you do to recover from failover?

Answer 15

Failover strategy:

• disk redundancy
• ability to replace hardware quickly
• 24/7 maintenance

Question 16

What is lossy compression?

Answer 16

Reduces a file by permanently eliminating certain information, especially redundant information.