Which of these statements is true?
A) Plastic is a conductor because it lets electricity flow through it.
B) Plastic is an insulator because it lets electricity flow through it.
C) Metals are conductors because they let electricity flow through them.
D) Metals are insulators because they let electricity flow through them.
What do these symbols show?
A) a cell and a bulb
B) a cell and a switch
C) a bulb and a switch
D a switch and a motor
Which instrument would you use to measure electric current?
A) an ammeter
B) a cell
C) a motor
D) a voltmeter
How big would the current be at X, Y and Z?
A) It would be biggest at X and smallest at Z. .
B) It would be biggest at Z and smallest at X
C) There would be no current at Y.
D) It would be the same at all three places.
You can make the current in a circuit smaller by:
A) putting a switch in the circuit.
B) putting more bulbs in the circuit.
C) taking some bulbs out of the circuit.
D) putting more cells in the circuit.
" Resistance" is a way of saying:
A) how much electricity is flowing.
B) how hard it is for electricity to flow.
C) how many cells are in a circuit.
D) how many switches are in a circuit.
Electricity is:
A) a source of energy.
B) a kind of liquid inside the wires.
C) tiny particles called electrons flowing through the wires.
D) tiny particles called atoms flowing through the wires.
A long wire:
A) has a smaller resistance than a short wire.
B) has the same resistance as a short wire.
C) has a bigger resistance than a short wire.
D) does not have resistance.
Which of these circuits are parallel circuits?
A) X and Y only
B) X and Z only
C) Y and Z only
D) all of them
Which switches must be pressed to make bulb X come on?
A) 1 and 2 only
B) 1 and 3 only
C) 2 and 3 only
D) all three of them
Parallel circuits are used for house lights:
A) so they can all be switched on and off together.
B) so you know when one breaks, because all the others go off
C) so they use a bigger current.
D) so they can all be switched on and off separately.
Which of the statements about this circuit can not be true?
A) The currents at Q and R add up to give the current at S.
B) The current is the same at P and S.
C) The current is the same at Q and R.
D) The current is the same at P and Q
When electricity flows through wires:
A) they melt.
B) they get cold.
C) they get hot.
D) nothing changes.
A fuse is:
A) a metal strip that bends when it is hot
B) a piece of wire that melts when it gets too hot.
C) a piece of plastic that does not let electricity through.
D) the part of a plug that sticks into a socket.
An electric heater has a current of 10 A flowing through it. Which fuse should be used?
A) 3 A
B) 5 A
C) 13 A
D) 30 A
A fuse is used to:
A) heat things.
B) make things move.
C) control the temperature of something.
D) stop electricity flowing if something is wrong.
If you touch electrical equipment with wet hands:
A) you might damage the equipment.
B) you could get an electrical shock
C) you might get your hands dirty.
D) you might make the equipment dirty.
What happens if a large electrical current flows through your body?
A) Your heart could stop working.
B) Your eyeballs could explode.
C) Nothing at all.
D) It will improve your circulation.
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