WorksheetsElectricity
Total questions: 30
Worksheet time: 15mins
The kWh is a unit of
current
energy
power
time
The diagram shows two resistors in parallel connected to a battery. The current from the battery is P and the currents through the resistors are Q and R.
What is the size of P?
Q ÷ R
Q − R
Q × R
Q + R
Diagram 1 shows two identical resistors R1 and R2 connected in series in a circuit. R2 is then removed as show in diagram 2.
A
B
C
D
A bulb in an electrical circuit has a current of 2A passing through it and a potential difference of 8V across it.
What is the power of the bulb?
0.016 kW
4 W
4 J
16 J
Which statement describes the behaviour of a battery?
It delivers conventional current from the negative to the positive terminal.
It delivers current when it is disconnected.
It delivers current when it is connected to a resistor.
It is made from two coils of wire would into a core of iron.
A television is fitted with a 3 A fuse and is connected to the 230 V mains supply. What is the purpose of the fuse?
To break the circuit when the current is greater than 3 A
To break the circuit when the mains supply is lower than 230 V
To keep the current in the circuit at 3 A
To keep the mains voltage at 230 V
The diagram shows a circuit.
The current at point P is 1.2 A. What is the current at point Q?
0.6 A
1.0 A
1.2 A
2.4 A
A circuit diagram contains the following symbol.
What does this symbol represent?
a fixed resistor
a fuse
a switch
a variable resistor
Electricity costs $0.20 per kWh. What is the cost of using a 0.5 kW heater for two hours?
$0.20
$0.50
$50
$200
A new electric saw has the following information displayed on the box:
1700 W
460 revolutions per minute
230 mm blade
6.9 kg
What is the power rating of the electric saw?
1700 W
460 revolutions per minute
230 mm
6.9 kg
This circuit is used to find the resistance of a length of wire.
A
B
C
D
A student builds a circuit containing two bulbs connected in series. A variable resistor is connected in parallel with the two bulbs.
Which diagram correctly represents this circuit?
A
B
C
D
The diagram shows an electric light.
Which part of the electric light will give an electric shock if touched?
bare copper wire
hard plastic lamp holder
soft plastic insulation
transparent glass bulb
Four identical resistors are connected in circuits E, F and G.
Which list gives the circuits in order of the effective resistances from the largest to smallest?
E, F, G
E, G, F
F, E, G
F, G, E
An electric kettle is found to use 36000 J of electrical energy in 30 seconds. What is the power of the kettle?
1200 W
18 000 W
72 000 W
1080000 W
Which part of an electric iron is the earth wire attached to?
the heating element
the live wire
the metal case
the plastic handle
An electric heater uses a current of 8 A when connected to a 250 V supply. How much energy is converted by the heater in 1 minute?
2000 J
16000 J
120000 J
960000 J
The diagram shows a circuit in which all bulbs are lit.
The bulb marked X blows and breaks part of the circuit.
How many of the bulbs will remain lit?
0
1
2
3
Which electrical device uses the most electrical energy in the times shown?
a 50 W light bulb in 250 s
a 100 W soldering iron in 150 s
a 500 W toaster in 50 s
a 1000 W heater in 20 s
Which term is a unit of current?
ampere
ohm
volt
watt
Ms Vino asks 4A to set up the circuit shown.
Which set of instructions would correctly help the students do this?
Connect the battery, the variable resistor, the bulb and the ammeter in series and then connect the voltmeter in parallel with the bulb.
Connect the bulb in series with the battery, the variable resistor and ammeter in parallel to each other and then connect the voltmeter in parallel to the bulb.
Connect the bulb, variable resistor and ammeter in parallel to the battery and then connect the voltmeter in series.
Connect the voltmeter in parallel to the battery, bulb, variable resistor and ammeter.
The diagram shows four circuits using resistors of the same value.
Which circuit has the greatest effective resistance?
A
B
C
D
What is the equation for calculating the electrical power produced in a resistor?
power = voltage x current
power = voltage ÷ current
power = voltage x current x time
power = voltage x current ÷ time
Where should a fuse always be connected?
in a separate circuit
in the earth wire
in the live wire
in the neutral wire
A student sets up the electrical circuit shown.
Which equation is correct for the readings on components A1 to A5?
A1 = A2 + A3+ A4 + A5
A1 = A2 + A3 + A5
A5 = A1 + A3 + A4
A5 = A2 + A3 + A4
The ceiling lamps in houses and the heating elements on an electric cooker are both connected in electrical circuits.
Which type of circuit is used in these situations?
A
B
C
D
Four circuit diagrams are shown.
Which circuit is set up correctly to measure voltage across and current through a lamp?
A
B
C
D
The diagram shows a circuit.
Which switches must be closed to light both lamps?
1 and 2 only
1 and 3 only
2 and 3 only
1, 2, and 3
A man uses four electrical appliances in his home. Which appliance costs the least to use for the time shown?
350 W for 9 hours
600 W for 5 hours
750 W for 4 hours
850 W for 3.5 hours
The cost of electricity is 20 cents per kWh. The average power of an air conditioner is 1.5 kW. How much does it cost to use the air conditioner for 10 hours?
30 cents
150 cents
200 cents
300 cents
