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2 questions · 3 marks
Computer systems manipulate bit patterns.
Convert the hexadecimal number 8F to denary.
Award one mark for:
143
Why: 8 × 16 + 15 = 143 (1).
248
Why: Takes the right-hand digit as the 16s, so the value is wrong.
23
Why: Adds the two digits instead of multiplying the first by 16.
Computer systems manipulate bit patterns.
Complete the table with the result of applying the shift to the binary pattern.
| Binary pattern | Shift | 8-bit binary result |
|---|---|---|
| 1000 0111 | Logical shift right by 1 |
Award one mark for each correct nibble in the correct order:
0 marks if the response is not 8-bit binary.
0100 0011
Why: Every bit moves 1 place right, with 0s in from the left: both nibbles are correct (2).
0100 0010
Why: A slip in the last bit. The first nibble is correct (1); the second is not.
0000 1110
Why: Shifts the bits the wrong way. Neither nibble is correct.
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