This document covers key concepts in electric circuits for grade 10 students. It defines potential difference as the work done per unit charge. It also defines current as the rate at which charges move past a fixed point, and resistance as anything that slows the flow of charge. Several sample problems are provided to calculate potential difference, current, energy, resistance, and time values. Key terms like coulomb, resistor, and potential difference are defined.

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