A heating element is connected across one cell, then across two cells. The potential difference (p.d.) across the heating element and the current in it are measured in each case.
For 1 cell, the p.d. is 3.2 V and the current is 0.20 A.
For 2 cells, the p.d. is 6.3 V and the current is 0.35 A.
What is the change in the resistance of the heating element when the number of cells is increased from one to two?
It decreases by 2.0 Ω2.0\ \Omega2.0 Ω.
It increases by 2.0 Ω2.0\ \Omega2.0 Ω.
It increases by 3.1 Ω3.1\ \Omega3.1 Ω.
It increases by 18.0 Ω18.0\ \Omega18.0 Ω.
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.