The average current during a lightning strike between a cloud and the ground is 2.5 × 104 A. The lightning releases 8.0 × 108 J of energy and lasts for 4.0 × 10-4 s. What is the average electromotive force (e.m.f.) between the cloud and the ground?
12.8 V12.8\text{ V}12.8 V
3.2×104 V3.2 \times 10^4\text{ V}3.2×104 V
8.0×107 V8.0 \times 10^7\text{ V}8.0×107 V
5.0×1016 V5.0 \times 10^{16}\text{ V}5.0×1016 V
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.