OCR J277- 1.2 Memory and storage

What numeric base does binary operate on? (1-4)

• 2

• 1

• 8

• 16

Answer explanation

Binary operates on base 2, using only two digits: 0 and 1. This is the fundamental principle of binary number systems, making '2' the correct answer.

How many bits are there in a byte? (1-4)

• 8

• 16

• 1

• 2

Answer explanation

A byte consists of 8 bits. This is a standard measurement in computing, making '8' the correct answer. The other options (16, 1, 2) do not represent the number of bits in a byte.

What is the maximum number of bits needed to represent 15 in denary? (3-5)

• 6

• 4

Answer explanation

To represent the number 15 in binary, we need 4 bits: 1111. The maximum value for 4 bits is 15 (2^4 - 1). Therefore, the correct answer is 4 bits.

What is the 8 bit binary representation of 17? (5-7)

• 00010010

• 00010001

• 00001101

• 00100010

Answer explanation

To convert the decimal number 17 to binary, we divide by 2 and record the remainders. 17 in binary is 10001. To represent it in 8 bits, we add leading zeros: 00010001. Thus, the correct answer is 00010001.

What is the binary representation of 32? (5-7)

• 00100000

• 00100100

• 00110000

• 00100001

Answer explanation

The binary representation of 32 is calculated as follows: 32 in decimal is 2^5, which corresponds to the binary 100000. In 8 bits, this is represented as 00100000, making it the correct choice.

What is the denary representation of this 8 bit number? 01001111 (5-7)

• 59

• 79

• 69

• 49

Answer explanation

The binary number 01001111 converts to denary by calculating 0*2^7 + 1*2^6 + 0*2^5 + 0*2^4 + 1*2^3 + 1*2^2 + 1*2^1 + 1*2^0 = 64 + 8 + 4 + 2 + 1 = 79. Thus, the correct answer is 79.

What is the denary representation of this 8 bit number? 11010101 (5-7)

• 199

• 206

• 228

• 213

Answer explanation

To convert the binary number 11010101 to denary, calculate: 1*2^7 + 1*2^6 + 0*2^5 + 1*2^4 + 0*2^3 + 1*2^2 + 0*2^1 + 1*2^0 = 128 + 64 + 0 + 16 + 0 + 4 + 0 + 1 = 213. Thus, the correct answer is 213.

How Bytes are there in a Terabyte? (5-7)

• 1024 Kilobytes

• 1024 Megabytes

• 1024 Gigabytes

Answer explanation

A Terabyte (TB) is equal to 1024 Gigabytes (GB). Therefore, the correct answer is 1024 Gigabytes, as it directly represents the conversion from Terabytes to Gigabytes.

Why do we use the binary number system in Computing?

• Because a CPU has two transistors

• To represent the two different states of transistors

• To allow the CPU to be in one of two states

Answer explanation

We use the binary number system in computing to represent the two different states of transistors, which can be either on or off. This allows computers to process and store information efficiently.

What is the hex number 6B in binary?

• 01101011

• 10101110

• 01110111

Answer explanation

The hex number 6B converts to binary by converting each hex digit: 6 = 0110 and B = 1011. Combining these gives 01101011, which is the correct binary representation.