A deep-sea research submersible is equipped with an external tungsten-halogen floodlight designed for a 48 V48\text{ V}48 V power supply.
Oscilloscope measurements show that when the floodlight is first switched on, the current transiently spikes to a very high peak before stabilizing at a constant operating current of 3.5 A3.5\text{ A}3.5 A.
Calculate the normal operating power of the floodlight.
Use the equation:
power=potential difference×current \text{power} = \text{potential difference} \times \text{current} power=potential difference×currentExplain why the initial current is much higher than the normal operating current of 3.5 A3.5\text{ A}3.5 A when the floodlight is first switched on.
39 exam-style questions on AQA GCSE Physics 2.1 Current, potential difference and resistance, covering 2.1.1 Standard circuit diagram symbols, 2.1.2 Electrical charge and current, 2.1.3 Current, resistance and potential difference, and 2.1.4 Resistors. Each one has a worked solution and a mark scheme showing where the marks go.