GCSE Standard Questions: Electricity in the Home
Q5. The graph shows how the current through a filament lamp changes after the lamp is switched on.
(a) The normal current through the filament lamp is 1.5 A.
Use the graph to determine how long the current through the filament lamp greater than 1.5 A
(b) Why might the filament inside a lamp melt when the lamp is first switched on?
(c) The lamp is connected to a 24 V power supply.
The current through the lamp is 1.5 A. Calculate the power of the lamp.
(d) LED lamps are much more efficient than filament lamps. Explain what this statement means.
(Total 8 marks)