A student measures the potential difference across a resistor and its resistance. Which calculation gives the current in the resistor?
potential difference×resistance\text{potential difference} \times \text{resistance}potential difference×resistance
potential difference÷resistance\text{potential difference} \div \text{resistance}potential difference÷resistance
resistance÷potential difference\text{resistance} \div \text{potential difference}resistance÷potential difference
potential difference+resistance\text{potential difference} + \text{resistance}potential difference+resistance
452 exam-style questions on CIE IGCSE Physics 4.2 Electrical quantities, covering 4.2.1a Positive and negative charge, 4.2.1b Charging by friction and detecting charge, 4.2.1c Electrical conductors and insulators, 4.2.1d Electric fields and electric field patterns, 4.2.2a Electric current, charge and measuring current, 4.2.2b Conduction in metals and the direction of current, 4.2.2c Direct current and alternating current, 4.2.3a Electromotive force, 4.2.3b Potential difference and voltmeters, 4.2.4a Resistance, 4.2.4b Resistance of a metallic wire, 4.2.4c Current–voltage graphs, and 4.2.5 Electrical energy and electrical power. Each one has a worked solution and a mark scheme showing where the marks go.