A1 and A2
A1 and A4
A2 and A3
A3 and A4
Switch 1 only
Switch 1 and switch 2 only
Switch 1 and switch 3 only
Switch 2 and switch 3 only
X lights more brightly than Y.
Y lights more brightly than X.
X and Y light with equal brightness.
Neither X nor Y light.
1, because they are in series, shine brighter and can be controlled independently.
1, because they are in parallel and shine brighter and can be controlled independently.
2, because they are in series and shine brighter and can be controlled independently.
2, because they are in parallel and shine brighter and can be controlled independently.
Lamp 1 ON, lamp 2 ON
Lamp 1 ON, lamp 2 OFF
Lamp 1 OFF, lamp 2 ON
Lamp 1 OFF, lamp 2 OFF
The current rating of the fuse was too high.
The current was too large.
The lamp was loose.
The voltage was too small.
To increase the circuit resistance
To keep the power used to a minimum value
To prevent a short-circuit from occurring
To stop the cables from carrying too much current
The cable gets hot and causes burns.
The circuit-breaker cuts off the current.
The current passes through water and causes a shock.
The tool rusts.
A fuse is included in a circuit to prevent the current becoming too high.
A fuse should be connected to the neutral wire in a plug.
An electric circuit will only work if it includes a fuse.
An earth wire is needed to prevent the fuse blowing.
Appliances not working