1. REVISION
CIRCUITS

3. CURRENT & THE FLOW OF ELECTRONS
ELECTRIC CURRENT is the amount of charge per second moving past a point in the conductor
1 COULOMB is the amount of charge that flows past a point in the circuit in 1 second when the current is 1A
AMMETER measure the rate of flow of charge

4. POTENTIAL DIFFERENCE & EMF
POTENTIAL DIFFERENCE between two points in a circuit is the difference in electrical potential energy per unit charge
EMF (electromotive force) is the amount of energy the battery is able to trasfer to 1C charge when the charge moves through the battery
VOLTMETER measure the amount of energy transferred to 1C charge

5. RESISTANCE & OHM
RESISTANCE is the opposition that a conductor offers to the flow of charge.
It is the ratio of voltage across the component to the current through the component
OHM: A conductor has a resistance of 1ohm as a current of 1A flows through it while a potensial difference of 1V is maintained
OHM'S LAW: The potential difference across a conductor is directly proportional to the current in the conductor at constant temperature..

6. The rate at which work is done
POWER
The rate at which work is done

7. COST OF ELECTRICITY
(kWh) refers to the use of 1 kilowatt of electricity for 1 hour.

8. EXAMPLE

9. RATIO PROBLEMS

10. OHMIC VS NON-OHMIC CONDUCTORS
Potensial difference (V)
Current (A)

11. OHMIC VS NON-OHMIC CONDUCTORS
Current (A)
Potensial difference (V)

13. EMF=17V
Ratio of resistance M to N
Internal resistance
Potential difference over N
Resistance of Y