Additional Mains Electricity
Basic Quiz on mains electricity and safety in the home
- 1.
A Cathode Ray Oscilloscope(CRO) is used to show a picture of the the changing voltage in an electrical circuit. The difference between a Direct Current(dc) and an Alternating Current(ac) is:-
- A.
Dc is a flat line and ac looks like a wave
- B.
Dc looks like a wave and ac is a flat line
- C.
Dc is a line up the screen and ac is a line across the screen
- D.
Dc is a line across the screen and ac is a line up the screen
- E.
Dc is a square and ac is a circle
Correct Answer
A. Dc is a flat line and ac looks like a wave -
- 2.
The earth wire has green and yellow stripes. This best reason for this choice is:-
- A.
There is no sensible colour to represent the earth.
- B.
The scientists could not agree on one colour
- C.
There were two different colours used in the previous systems
- D.
It allows colour blind people to identify the earth
- E.
The stripe looks more fashionable
Correct Answer
D. It allows colour blind people to identify the earth -
- 3.
What is the colour of the live wire and where is it connected?
- A.
Blue and connected to the Left pin
- B.
Blue and connected to the Right pin
- C.
Brown and connected to the Left pin
- D.
Brown and connected to the Right pin
- E.
Green and Yellow and connected to the Top pin
Correct Answer
D. Brown and connected to the Right pin -
- 4.
The main purpose of the earth wire is:-
- A.
To prevent explosions
- B.
To prevent electric shocks
- C.
To prevent fires
- D.
To keep the appliance working
- E.
To complete the electric circuit
Correct Answer
B. To prevent electric shocks -
- 5.
What type of electrical appliance will have an earth wire connected to it?
- A.
All powerful appliances
- B.
All heating appliances
- C.
Any appliance in a plastic case
- D.
Any appliance in a wooden case
- E.
Any appliance in a metal case
Correct Answer
E. Any appliance in a metal case -
- 6.
You have the choice of a 1A, 3A, 5A, 10A or 13A fuse. Which one would you fit to a 1250W hair dryer to work with 250V mains?
- A.
1A
- B.
3A
- C.
5A
- D.
10A
- E.
13A
Correct Answer
D. 10AExplanation
The hairdryer needs 5A of current to work, the best fuse is the smallest value that is BIGGER than this currentRate this question:
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- 7.
A current of 12A flows through through a kettle for 5 mins while it boils some water. How much CHARGE flows through the kettle?
- A.
1.4C
- B.
17C
- C.
60C
- D.
300C
- E.
3600C
Correct Answer
E. 3600C -
- 8.
A TV recieves 4800J of energy from 20C of charge. What is the potential difference across the TV?
- A.
240V
- B.
2400V
- C.
4820V
- D.
9600V
- E.
96000V
Correct Answer
A. 240V -
- 9.
A 9.9kW shower heater is used with 220V mains. What current flows through the heater?
- A.
0.45A
- B.
4.5A
- C.
45A
- D.
210.1A
- E.
229.9A
Correct Answer
C. 45A -
- 10.
THe two key reasons why circuit breakers are used instead of fuses are:-
- A.
They work faster and they are cheaper
- B.
They work faster and they are easier to reset
- C.
They are cheaper and they are easier to reset
- D.
Fuses are expensive and it takes time to find the correct one.
- E.
Fuses can give off toxic fumes and are difficult to replace
Correct Answer
B. They work faster and they are easier to reset -
Quiz Review Timeline +
Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.
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Current Version
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Jul 30, 2011Quiz Edited by
ProProfs Editorial Team -
Jan 14, 2010Quiz Created by
Stephen Carpente
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