The resistance of a 1.0 m1.0\text{ m}1.0 m length of resistance wire is 8.0 Ω8.0\ \Omega8.0 Ω. Under experimental conditions, a crocodile clip is connected to one end of the wire at the 0 m0\text{ m}0 m mark of a metre rule. A movable contact can touch the wire at any position along its length lll from the 0 m0\text{ m}0 m mark.
Describe the expected orientation and shape of a graph showing how the resistance RRR of the wire varies with length lll as lll increases from 000 to 1.0 m1.0\text{ m}1.0 m. State the coordinates of the endpoints of this graph.
A battery of electromotive force (e.m.f.) 12 V12\text{ V}12 V with negligible internal resistance is connected across the entire 1.0 m1.0\text{ m}1.0 m length of the resistance wire.
State what is meant by electromotive force (e.m.f.).
A battery of electromotive force (e.m.f.) 12 V12\text{ V}12 V with negligible internal resistance is connected across the entire 1.0 m1.0\text{ m}1.0 m length of the resistance wire.
Calculate the current in the resistance wire.
A battery of electromotive force (e.m.f.) 12 V12\text{ V}12 V with negligible internal resistance is connected across the entire 1.0 m1.0\text{ m}1.0 m length of the resistance wire.
Calculate the potential difference (p.d.) across a length l=0.45 ml = 0.45\text{ m}l=0.45 m of the wire.
A battery of electromotive force (e.m.f.) 12 V12\text{ V}12 V with negligible internal resistance is connected across the entire 1.0 m1.0\text{ m}1.0 m length of the resistance wire.
Calculate the charge that passes through the resistance wire in 6.5 minutes6.5\text{ minutes}6.5 minutes.
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.