An electrical component of resistance R R\,R is connected in a circuit. There is a potential difference V V\,V across the component, resulting in a current III. In a time interval ttt, a charge Q Q\,Q flows through the component and an electrical energy W W\,W is dissipated.
Which expression is correct?
Q=VItQ = V I tQ=VIt
W=I2RtW = I^2 R tW=I2Rt
W=V2RtW = \frac{V^2}{R t}W=RtV2
Q=ItQ = \frac{I}{t}Q=tI
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.