Unit 2: Data Representation

Question 1

What is Binary Shift?

Answer 1

A binary shift is when the digits of a binary are moved either to the left or the right for multiplicative or division purposes. These are usually faster faster than normal multiplication and division.

A left shit represents multiplication by 2. All digits are shifted one position to the left and a 0 is added to fill in the gap at the end.

In a left shit, if a digit falls off the end, this is an overflow error.

A right shift represents division by 2. Alldigits are moved 1 position to the right and a 0 is added to fill the gap at the start.

In a right shift, if a 1 digit falls off the end, this is an underflow error.

Question 2

What do scientists use ‘1’ and ‘0’ for?

Answer 2

To represent that

1 is ON
0 is OFF

Question 3

How do you convert from Binary to Hexadecimal?

Answer 3

1. Split the binary string up into nibbles (remember a nibble = 4 bits)
2. Work out the decimal value for each nibble
3. Convert the decimal value into it’s hex equivalent
4. String together the hex values

Question 4

How do you convert from Hexadecimal to Decimal?

Answer 4

1. Write the place headings above the hexadecimal digits.
2. If there are letters, convert them to their decimal equivalent.
3. Multiply the value by the place heading.
4. Add these values together

Question 5

How do you convert from Decimal to Hexadecimal?

Answer 5

1. Work out how many 16s there are in the number
2. Write this number under the 16s column
3. Write the remainder under the 1s column
4. Covert these to hexadecimal digits (if applicable)

Question 6

What is meant by a character set?

Answer 6

All characters, including letters, numbers and punctuation, they are all represented by binary numbers.