define electric current.
describe the concept of conventional current.
understand the potential difference across a circuit component and name its unit.
describe Ohm's law and its limitations.
define resistance and its unit(Ω).
calculate the equivalent resistance of a number of resistances connected in series and also in parallel.
describe the factors affecting the resistance of a metallic conductor.
distinguish between conductors and insulators.
sketch and interpret the V- I characteristics graph for a metallic conductor, a filament lamp and a thermistor.
describe how energy is dissipated in a resistance and explain Joule's law.
apply the equation \(E = I \cdot Vt = I^2 Rt = V^2 t / R\) to solve numerical problem.
calculate the cost of energy when given the cost per kWh.
distinguish between D.C and A.C.
identify circuit components such as switches, resistors, batteries etc.
describe the use of electrical measuring devices like galvanometer, ammeter and voltmeter (construction and working principles not required).
construct simple series (single path) and parallel circuits (multiple paths).
predict the behaviour of light bulbs in series and parallel circuit such as for celebration lights.
state the functions of the live, neutral and earthwires in the domestic main supply.
state reason why domestic supplies are connected in parallel.
describe hazards of electricity (damage insulation, overheating of cables, damp conditions).
explain the use of safety measures in household electricity, (fuse, circuit breaker, earthwire).

Current Electricity - Introduction and Learning Outcomes

After studying this unit, students will be able to: