Page 148 - Knowledge Organiser Yr9 24-25

Knowledge Base: Science P2: Electricity Year 9
Help Box 1: Circuit Symbols
Circuit diagrams use standard symbols.
1. Drawing circuits
1.1
In what type of circuit are all the components in one loop?
Series
1.2
In what type of circuit are the components in multiple loops?
Parallel
1.3
In a circuit, one component breaks and all the components stop working, what type of circuit is it?
Series
1.4
In a circuit, one component breaks and all the other components still work. What type of circuit is it?
Parallel
2. Charge and current
2.1
What is needed for an electrical charge to flow?
A complete circuit and a source of potential difference.
2.2
What does the word rate mean?
Per second
2.3
Define current.
The rate of flow of charge
2.4
What symbol is used instead of writing the word "current"?
I
2.5
State the unit of current.
Amps or A
2.6
What symbol is used instead of writing the word "charge"?
Q
2.7
What is the unit of charge?
Coulombs or C
2.8
What is meant by 1 Amp?
1 Coulomb per second
2.9
State the equation that links charge, current and time.
Charge flow = current x time
2.10
Give the symbol equation that links charge flow, current and time.
Q=It
2.11
State the current rule for components connected in series.
The current is the same through each component.
2.12
State the current rule for components connected in parallel.
The total current of the circuit is the sum of the current through each branch of the circuit.
Worked example question:
A battery charger passes a current of 2A through a cell over 30 minutes.
How much charge is transferred to the cell?
Help Box 2: Electricity Variables
Q
charge flow
Coulombs (C)
t
time
Seconds (s)
V
potential difference
Volts (V)
I
current
Amps (A)
P
power
Watts (W)
E
energy
Joules (J)
R
resistance
Ohms (Ω)
148