Four wires are made of the same metal.
Which wire has the least resistance?
a 150 cm150\text{ cm}150 cm long wire with a diameter of 2.0 mm2.0\text{ mm}2.0 mm
a 150 cm150\text{ cm}150 cm long wire with a diameter of 4.0 mm4.0\text{ mm}4.0 mm
a 50 cm50\text{ cm}50 cm long wire with a diameter of 2.0 mm2.0\text{ mm}2.0 mm
a 50 cm50\text{ cm}50 cm long wire with a diameter of 4.0 mm4.0\text{ mm}4.0 mm
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.