Mock 1 Notes

Question 1

Give three advantages of wireless connectivity

Answer 1

• Easy installation
• Cheap
• Good mobility for users

Question 2

How does lossy compression compress images?

Answer 2

Algorithms analyse the image and find areas with only slight colour differences. These are given the same value and the file is rewritten using fewer bits.

Question 3

How does lossy compression compress sound?

Answer 3

Very small variations in frequency, tone and volume are removed as the human ear cannot detect these small differences.

Question 4

What is stored in RAM?

Answer 4

Data and instructions when an application is running (OS, applications, GUI)

Question 5

Give two ways that e-waste could be harmful to human health

Answer 5

• Waste might be illegally dumped in landfill where toxic substances can get into the land and water
• Burning digital devices releases toxins into the air which could then be inhaled

Question 6

What is checked for in a code review?

Answer 6

Check for:

• logic errors
• security vulnerabilities
• inefficient code
• bad programming practice

Question 7

What are the features of a compiler?

Answer 7

• Returns an executable file
• Protects source code from competitors
• Entire source code is converted at once
• Error report is provided at the end

Question 8

How does a router direct data over the internet?

Answer 8

• Reads packet to find recipient address
• Has physical connections to >=2 networks
• Holds a routing table
• Forwards data/packets
• Chooses most efficient path to the next node

Question 9

What’s the best case scenario for a binary search algorithm?

Answer 9

Search item is the median

Question 10

What’s the worst case scenario for a binary search algorithm?

Answer 10

The search item is at the point where the final division could be made