﻿ SmartLearner ## Electric Circuits

(This section must be read in conjunction with the CAPS, p. 88–89 & 121.)

### Ohm's Law

• State Ohm's law in words:
The potential difference across a conductor is directly proportional to the current in the conductor at constant temperature.
• Determine the relationship between current, potential difference and resistance at constant temperature using a simple circuit.
• State the difference between ohmic conductors and non-ohmic conductors and give an example of each.
• Solve problems using: for series and parallel circuits (maximum four resistors).

### Power, Energy

• Define power as the rate at which work is done.
• Solve problems using: • Solve problems using: • Solve circuit problems involving the concepts of power and electrical energy.
• Deduce that the kilowatt hour (kWh) refers to the use of 1 kilowatt of electricity for 1 hour.
• Calculate the cost of electricity usage given the power specifications of the appliances used, the duration and the cost of 1 kWh.

### Internal resistance, series and parallel networks

• Solve problems involving current, voltage and resistance for circuits containing arrangements of resistors in series and in parallel (maximum four resistors).
• Explain the term internal resistance.
• Solve circuit problems using: • Solve circuit problems, with internal resistance, involving series-parallel networks of resistors (maximum four resistors).