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WorksheetsGrade 9: Electricity Revision 2
Total questions: 15
Worksheet time: 10mins
The following statements about a circuit overload are true except ______:
Too much current can cause overheating and possibly a fire
The current in the circuit is linked to the power rating of the appliance
Too many appliances on one circuit will overload the circuit
Overloading happens when 1 or 2 appliances are being used at a time.
Choose the correct phrase to complete the following sentence: Earthing is_________
Current running through an unintended path
Instantaneous discharge directly to the earth
A thin wire that will melt and break the circuit when overloaded
A flow of electrons through the neutral wire
The purpose of a 3-point plug is to:
Draw a greater current to operate appliances.
Make it easier to plug in.
It has an earth wire as a safety protector
Provide a closed circuit by connecting the live and neutral wires
A thin wire that will melt and break the circuit when overloaded is called a:
Trip switch
Fuse
Earth leakage
rheostat
In a three point plug _____
The green and yellow wire complete the circuit for the flow of current
The blue and brown wires need to be connected to each other in order to conduct the current
The green and yellow wire connects to the metal casing of an appliance for safety
The blue wire is live and the brown is neutral
An example of a renewable energy source is
Uranium
Wind
Coal
Natural Gas
An example of a non-renewable energy resource is:
Wind
Crude oil
Waves
The sun
The following are all examples of fossil fuels, except:
Crude oil
Uranium
Natural Gas
Coal
Hydroelectric power can be provided by all of the following except:
A thunderstorm
Waves
Dams
Falling water
Two hydrogen atoms merging to form a helium atom and large amounts of energy is an example of:
A non-renewable power sorce
Nuclear fission
Nuclear fusion
Hydrogen power
The unit for the consumption of electrical energy in a household is:
Watt/second
kWh
Joule
Watt
A bulb has a power rating of 60W. The electricity consumed by the bulb in 6 hours will be:
36 Units
3,6 Units
0.36 Units
360 Units
A kettle with a power rating of 2 500 W is used to boil water for 3 minutes. How many units of electrical energy are consumed each time the kettle is boiled?
0.75kWh
0,125kWh
7,5 kWh
12,5kWh
Thato lives in an apartment that has a hot water geyser that has a power rating of
1500W. To save electricity she switches it off for 5 hours a day. How much money will she save on her electricity account each time she does this if electricity is charged at 250c per unit?
R1,87
R7.50
1875c
187,5c
A coal power station operates as follows
Coal → furnace → steam → turbine → generator
Coal → Steam → generator → turbine → furnace
Furnace → coal → crusher → turbine → generator
Neutrons bombard uranium nucleus → turbine → generator
