Memory and Storage

Question 1

What is RAM?

Answer 1

Volatile memory that stores data and programs currently in use.

Question 2

What is ROM?

Answer 2

Non-volatile memory storing essential instructions.

Question 3

What’s the difference between RAM and ROM?

Answer 3

RAM is volatile (loses all its data when shut off) while ROM. RAM can be read and written to while ROM is read only.

Question 4

What is virtual memory?

Answer 4

Space on secondary storage used as extra RAM when RAM is full.

Question 5

Why is virtual memory slower than RAM?

Answer 5

Because it is stored on a hard drive or SSD, which is slower to access.

Question 6

What happens when the CPU uses virtual memory too much?

Answer 6

The system slows down (known as “disk thrashing”).

Question 7

What are the three types of secondary storage? Give an example for each of them.

Answer 7

Magnetic (Hard Disk Drive (HDD), optical (CD, DVD, Blu-ray), and solid-state (Solid State Drive), Universal Serial Bus (USB).

Question 7

How does magnetic storage work?

Answer 7

Uses spinning disks and read/write heads to store data magnetically.

Question 8

How does optical storage work?

Answer 8

Uses lasers to read/write pits on a disc surface.

Question 9

How does solid-state storage work?

Answer 9

Uses flash memory and electrical circuits, with no moving parts.

Question 10

Which storage type is fastest?

Answer 10

Solid-state (SSD).

Question 11

Which storage type is cheapest per GB?

Answer 11

Magnetic (HDD).

Question 12

Which storage type is most durable?

Answer 12

Solid-state (no moving parts).

Question 13

What three factors are used to compare storage devices?

Answer 13

Capacity, speed, durability.

Question 14

Why is SSD better for performance than HDD?

Answer 14

It has faster read/write speeds and no moving parts.

Question 15

What is 1 byte equal to?

Answer 15

8 bits.

Question 16

What is a nibble?

Answer 16

4 bits (half a byte).

Question 17

Arrange these from smallest to largest: nibble, kilobyte, terabyte, byte, bit, gigabyte, petabyte, megabyte.

Answer 17

bit (1), nibble (4/half a byte), byte (8), kilobyte (1000 bytes), megabyte (1000 KB), gigabyte (1000 MB), terabyte (1000 GB), petabyte (1000 TB)

Question 18

What is binary and why do computers use them?

Answer 18

Because they operate using electrical signals (on/off). Computers use them because they operate using electrical signals (on/off).

Question 19

Convert the binary number 101101 to denary.

Answer 19

1 0 1 1 0 1
= 32 + 0 + 8 + 4 + 0 + 1
= 45

Question 20

Convert the denary number 57 to binary.

Answer 20

57 → 32 + 16 + 8 + 1
= 00111001

Question 21

Convert binary 11110000 to hexadecimal.

Answer 21

Break into nibbles: 1111 | 0000
1111 = F
0000 = 0
= F0
10 11 12 13 14 15
A B C D E F

Question 22

Convert denary 255 to hexadecimal.

Answer 22

128 64 32 16 8 4 2 1
1 1 1 1 1 1 1 1
8 4 2 1 8 4 2 1
1 1 1 1 | 1 1 1 1
15 15
10 11 12 13 14 15
A B C D E F
FF

Question 23

Q: What is resolution?

Answer 23

A: Number of pixels in an image (width × height).

Question 24

Q: What is colour depth?

Answer 24

A: Number of bits used per pixel.

Question 25

How does colour depth affect file size?

Answer 25

A: Higher colour depth → larger file size.

Question 26

How does resolution affect file size?

Answer 26

A: More pixels → larger file.

Question 27

What is sample rate?

Answer 27

A: Number of samples taken per second (Hz).

Question 27

What is bit depth in sound?

Answer 27

A: Number of bits used per sample.

Question 28

How do sample rate and bit depth affect sound?

Answer 28

A: Higher values give better quality but larger file size.

Question 29

What is compression?

Answer 29

A: Reducing the size of a file.

Question 30

What is lossy compression?

Answer 30

A: Permanently removes unnecessary data (e.g., MP3, JPEG).

Question 31

What is lossless compression?

Answer 31

A: Removes redundancy but no data is lost (e.g., ZIP, PNG).

Question 32

Which compression type gives the smallest file size?

Answer 32

A: Lossy.