1. Grade 10 - Electric Circuits May 25, 2012
Grade 10
Electric Circuits
Circuit Symbols
Component Symbol
Connector
Cell
Battery
Light Bulb
Resistor
Open Switch
Closed Switch
Ammeter
Voltmeter
Grade 10
Potential Difference
Definition:
Potential difference is the work done per
unit charge
Unit: Volt (joule per coulomb)
V = W
Q
Emf: Potential difference across the terminal of
a battery that is not in a complete circuit.
Voltmeter

2. Grade 10 - Electric Circuits May 25, 2012
Grade 10
Problem:
Calculate the potential difference
across a light bulb if 100J of work is
done when 15 C of charge moves
through the bulb.
Grade 10
Problem:
How much energy is transferred
when 35 C of charge moves
through a resistor with a potential
difference of 12V?

3. Grade 10 - Electric Circuits May 25, 2012
Grade 10
Current
Definition:
The rate at which charges moves past a
fixed point in a circuit
Unit: ampere(coulomb per second)
I = Q
t
Ammeter
Grade 10
Problem
An amount of charge equal to 72 C
moves past a point in a circuit in
5 seconds, what is the current in
the circuit?

4. Grade 10 - Electric Circuits May 25, 2012
Grade 10
Problem
How long does it take 105 C of
charge to moves pass a point in
a circuit if the current is 2 A?
Grade 10
Resistance
Definition:
Resistance slows down the flow of charge
in a circuit.
Unit: ohm (Ω) (volt per ampere of current)
R = V
I
Ohm’s Law
The potential difference over a resistor is
directly proportional to the current through
the resistor provided the temperature of the
resistor remains constant.

5. Grade 10 - Electric Circuits May 25, 2012
Grade 10
Problem
The current through a resistor is 2A.
Calculate the resistance of the resistor if the
potential difference across the resistor is 25 V.
Grade 10
Problem
The potential difference across a
resistor of 15 Ω is 12 V. Calculate the
current through the resistor.

6. Grade 10 - Electric Circuits May 25, 2012
Grade 10
Problem
Define the following:
1] Resistor
2] Coulomb
3] Potential difference
Grade 10

7. Grade 10 - Electric Circuits May 25, 2012
Grade 10
Grade 10

8. Grade 10 - Electric Circuits May 25, 2012
Grade 10