Page 142 - Knowledge Organiser Yr7 24-25

4. Parallel Circuits
4.1
How are components arranged in a parallel circuit?
In more than one branch
4.2
Draw a parallel circuit with two bulbs and a cell
4.3
How does current behave in a parallel circuit?
Current in each branch of a parallel circuit is equal to the total current in the entire circuit
7. Power and Electricity Costs
7.1
What is electrical power?
The rate at which energy is transferred by a circuit
7.2 How is electrical power calculated?
7.3 What is the unit for power?
7.4 What is 1kW?
Power = energy transferred ÷ time (s)
Watts (W)
1000W
7.5
What is the purpose of an electrical metre in your home?
For energy companies to monitor the amount of energy transferred to our homes to generate a bill
7.6
If an electrical appliance has a large power rating what does this mean?
It is able to transfer energy quickly
7.7
What unit is used by energy companies for ‘energy transferred’ instead of joules?
kWh (kilowatt hour)
7.8
What is 1kWh?
The amount of energy transferred to a 1kW appliance in an hour
7.9
How is the amount of energy transferred calculated?
Energy transferred = power x time (h)
5. Resistance
5.1
What is meant by electrical resistance?
A measure of how much a material reduces the flow of charge (the current)
5.2 What is the unit of resistance?
Ohms (Ω)
5.3
What effect will adding more components to a circuit have on the resistance and current in the circuit?
The resistance will increase The current will decrease
6. Circuit Problems
5.1
What is the missing reading in this diagram? Why?
0.3A as current is the same throughout the series circuit
5.2
What is the missing reading in this diagram? Why?
0.6A as current in all the branches of a parallel circuit add up to make the total current
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Knowledge Base: Science 7.10 Electricity Year 7