A metal wire of a fixed volume is stretched to different lengths LLL, resulting in a different resistance R R\,R for each length.
Which relationship between R R\,R and L L\,L is correct?
RRR is directly proportional to LLL.
RRR is directly proportional to L2L^2L2.
RRR is inversely proportional to LLL.
RRR is inversely proportional to L2L^2L2.
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.