Simple Circuits
State what happens to the current at different points in a series circuit.
The current is the same at all points in a series circuit.
Name the two types of electric charge.
Positive and negative.
State the unit of current.
Amps (A).
What device measures Voltage?
Voltmeter
Which pathway is energy transferred by the battery to the current?
Electrical pathway
A circuit contains one battery and one lamp connected in a loop.
How many paths does the current have?
There is one path for the current.
Describe what happens when two like charges are brought close together.
They repel each other.
Which device is used to measure current?
What store of energy does a battery have?
Chemical Store
A 2 kW heater runs for 2 hours. Calculate the energy transferred.
Energy = Power × Time
Energy = 2 × 2
Energy = 4kWh
A second identical bulb is added in series.
Describe what happens to the brightness of the bulbs and explain why.
The bulbs become dimmer because the total resistance increases, which reduces the current.
Electrostatic force
Which Force acts between charged objects?
10 C of charge flows in 2 seconds. Calculate the current.
Current =charge ÷ time
Current =charge ÷ time
Current = 10 ÷ 2
Current = 5A
A device operates at 12 V and 2 A. Calculate its power.
Use Power = Voltage x Current
Power = Voltage x Current
P = 12 × 2
P = 24
The power is 24 W.
Explain why a kettle has a higher power rating than a phone charger.
A kettle transfers energy much faster to heat water
A 6 V battery is connected to two identical bulbs in series.
Calculate the voltage across each bulb.
Each bulb has 3 V across it.
Which energy store does a moving fan have?
Kinetic energy
In which direction does current flow?
Positive to negative
If more bulbs are added in series, what happens to the current?
The current decreases.
A circuit is left on. What happens to the battery's energy store?
Energy store decreases.
A student says:
“The first bulb will be brighter because it is closer to the battery.”
Explain why this is incorrect.
In a series circuit, the current is the same everywhere. Both bulbs receive the same current, so they are equally bright.
How does adding a cell/ battery change current.
Current will increase.
A current of 3 A flows for 4 minutes. Calculate the total charge transferred.
4 minutes = 4 × 60 = 240 seconds
Charge = current x Time
Charge = 3A x 240s = 720C
A 9 V battery powers two components in series.
One component has 3 V across it.
Calculate the voltage across the second component.
Total voltage = 9 V
9 − 3 = 6 V
A 2 kW heater and a 0.1 kW television are both used for 3 hours.
Calculate the energy used by each and explain which costs more to run.
Heater: 2 × 3 = 6 kWh
TV: 0.1 × 3 = 0.3 kWh
Heater costs more to run.