In a laboratory, a student connects a circuit consisting of a battery, a switch, an ammeter, a lamp, and a light-dependent resistor (LDR) all in series.
Explain how the ammeter is connected in the circuit to measure the current, and describe the standard circuit diagram symbol for an LDR.
The potential difference across the lamp is 6.0 V6.0\text{ V}6.0 V and the current in the lamp is 0.25 A0.25\text{ A}0.25 A. Calculate the resistance of the lamp.
The lamp is switched on for 40 s40\text{ s}40 s. Calculate the total electrical energy transferred in the lamp during this time.
The student now shines a bright flashlight onto the LDR, increasing the light intensity. State and explain what happens to the current in the circuit.
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.