A 12 V battery powers an outdoor garden lighting circuit containing a master switch, a protective fuse located close to the battery, and two lamps, L1 L_1\,L1 and L2L_2L2, connected in parallel so they can operate independently.
Draw the circuit diagram for this garden lighting system, using conventional electrical symbols.
The battery has an electromotive force (e.m.f.) of 12 V. When the switch is closed, a current of 0.80 A flows through each lamp. Calculate the resistance of one of these lamps and state the unit.
On one occasion, when the master switch is turned on, lamp L1 L_1\,L1 lights up, but lamp L2 L_2\,L2 fails to light up. Suggest one possible reason for this.
While inspecting the circuit, a person accidentally connects a wire across the terminals of lamp L2L_2L2, short-circuiting it. When the switch is closed with this short-circuit in place, state what happens, if anything, to: (i) the fuse, (ii) lamp L1L_1L1, (iii) lamp L2L_2L2.
136 exam-style questions on CIE IGCSE Physics 4.3 Electric circuits, covering 4.3.1a Circuit diagrams and circuit components, 4.3.2a Series circuits, 4.3.2b Parallel circuits, 4.3.2c Current and potential difference in circuits, 4.3.2d Combined resistance of resistors in parallel, and 4.3.3 Action and use of circuit components. Each one has a worked solution and a mark scheme showing where the marks go.