A digital flight data recorder (FDR) measures an aircraft's absolute altitude (in metres) above sea level, which is guaranteed to be non-negative. The system allocates exactly 12 bits to store this altitude as an integer.
Which of the following statements correctly describes the range advantage of using an unsigned 12-bit integer instead of a 12-bit two's complement signed integer for this measurement?
The unsigned representation allows a maximum altitude that is exactly 2048 m2048\text{ m}2048 m higher than the signed representation.
The unsigned representation allows a maximum altitude that is exactly 2047 m2047\text{ m}2047 m higher than the signed representation.
The unsigned representation allows a maximum altitude that is exactly 4095 m4095\text{ m}4095 m higher than the signed representation.
The unsigned representation allows a maximum altitude that is exactly 1024 m1024\text{ m}1024 m higher than the signed representation.
117 exam-style questions on Edexcel GCSE Computer Science Binary, covering Binary representation and number of states, Unsigned and two's complement integers, Converting denary and 8-bit binary, Binary addition and binary shifts, Concept of overflow, and Hexadecimal notation and conversion. Each one has a worked solution and a mark scheme showing where the marks go.