A student is setting up equipment for an experiment and needs to convert between SI units and their prefixes. The student records a current of 0.045 A, a frequency of 3 500 000 Hz, a length of 0.000 012 m, a time of 0.000 000 250 s, and a mass of 6 200 g. Express each measurement using an appropriate SI prefix, giving the correct prefix symbol in each case.

AQA A-Level Physics (7408) — 3.1.1 Use of SI Units and Their Prefixes · State · 5 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Model answer (5 marks)

Current: 45 mA
Frequency: 3.5 MHz
Length: 12 μm
Time: 250 ns
Mass: 6.2 kg

Examiner tips

  • Use the correct prefix symbol (m, M, μ, n, k) and match the unit (A, Hz, m, s, kg).
  • Write the value with the appropriate number of significant figures as given in the mark scheme.
  • Ensure the prefix is placed directly before the unit without a space.

Mark scheme (5 marks)

  1. Current: 45 mA (milliamps / milliamperes)
  2. Frequency: 3.5 MHz (megahertz)
  3. Length: 12 μm (micrometres)
  4. Time: 250 ns (nanoseconds)
  5. Mass: 6.2 kg (kilograms)

Key terms in this question

SI units · prefix

Related

More Use of SI Units and Their Prefixes questions

▶ Try answering this question with AI marking (free) →