Electrical Resistance Unit — FRCA Primary MCQ
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Correct answer: E — Ohm
E. The ohm (Ω) is the SI derived unit of electrical resistance. From Ohm's law, V = IR, resistance is R = V/I; therefore 1 Ω = 1 V A⁻¹. Equivalently, a conductor has a resistance of one ohm when a potential difference of one volt produces a current of one ampere under constant physical conditions. The other options are different electrical units: the farad measures capacitance, the ampere measures electric current, the watt measures power, and the volt measures potential difference or electromotive force.
Reference: Ofqual. GCSE Subject Level Conditions and Requirements for Combined Science, Appendix 2: SI units in science. 2015. https://assets.publishing.service.gov.uk/media/5d35b71aed915d0d083f29b7/gcse-subject-level-conditions-and-requirements-for-combined-science.pdf