GCSE Standard Questions: Electric Circuits
Q13.
(a) Clark investigated how the current in a circuit varied with the number of lamps box connected in parallel in the circuit. The diagram below shows the circuit with three identical lamps connected in parallel.
And here is the graph of his results:
(i) Complete the sentence below by choosing a word/phrase from the box as your answer - each one can be used once, more than once or not at all.
decreased |
stayed the same |
increased |
As the number of lamps increased, the current _ _ _ _ _ _ _ _ , the total resistance of the circuit _ _ _ _ _ _ _ _ and the potential difference across the battery _ _ _ _ _ _ _ _ .
[3 marks]
(ii) When there were three lamps in the circuit the digital ammeter reading kept changing between 0.35 A and 0.36 A.
What type of error would this lead to?
[1 mark]
(b) The diagram below shows a circuit with five ammeters and three identical lamps.
(i) Complete the table below and give the readings that you would expect to see on ammeters A2 and A5
Ammeter |
A1 |
A2 |
A3 |
A4 |
A5 |
Current in amps |
0.36 |
|
0.12 |
0.12 |
|
[2 marks]
(ii) The resistance of one lamp is 15 Ω.
If the current flowing through the lamp is 0.12 A, calculate the power output of the lamp.
[3 marks]
(Total 9 marks)