1. Twenty Questions
Electricity 2

2. Twenty Questions 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

3. 1. Give 1 advantage of using a circuit breaker.
Reset instead of replaced.
Easier to see if it’s off.

4. 2. What type of appliance uses the greatest power?
One which produces heat.

5. 3. Upon what does the size of an appliances flex depend?
It’s power rating.

6. 4. In a house in what configuration are the wiring circuits?
Parallel.

7. 5. Name the 3 wires in a plug.
Live
Neutral
Earth

8. 6. Describe the electrical field surrounding a negative point charge.

9. 7. What type of circuit is shown?
Ring mains circuit.

10. 8. Describe the symbol for a fuse.
Rectangle with the wire passing through it.

11. 9. What does “double insulated” mean?
An appliance which has a plastic casing.

12. 10. Explain how the Earth wire works?
At the appliance end the Earth wire is connected to the metal casing of the appliance so that, if a fault develops making the casing live a large current passes and blows the fuse.
This prevents anyone touching the casing from getting a shock.

13. 11. Calculate the current in a circuit if 135 charges take 3minutes to travel through the circuit.
Q = I t
I = Q/t
I = 135/180
I = 0.75A

14. 12. What are the values of the voltage and frequency of the mains supply?
50Hz

15. The flow of electric charges around a circuit.
13. What is current?
The flow of electric charges around a circuit.

16. The flow of electric charges around a circuit.
13. What is current?
The flow of electric charges around a circuit.

17. 14. What are the units for charge?
Coulombs

18. 15. What type of energy is gained when work is done moving a charge between two plates?
Kinetic

19. 16. What danger is present when using a multiway adapter?
If too many appliances are used or ones which require much current are used it may overheat and catch fire.

20. 17. Calculate the electrical potential energy gained by an electron moving between two plates which have a potential difference of 300V, Qelectron = 1.6x10-19 C
W=QV
W=1.6X10-19X300
W=4.8X10-16J

21. 18. What type of current is shown by the waveform?
a.c / alternating current

22. It melts when it’s rating/value has been reached
19. Why must the fuse value be greater than the current used by the appliance?
It melts when it’s rating/value has been reached

23. 20. What fuse would be used in a 2kW kettle?
I=P/V
I=2000/230
I=8.7A
10A fuse.