Electricity & Magnetism
- 2 subtopics
- 1 simulation
- High weightage
4.1 Ohm’s law and resistance
Ohm’s law states that the current flowing through a metallic wire is directly proportional to the potential difference across its ends, provided the physical conditions (such as temperature) stay constant.
V = I × R
Change the voltage and resistance yourself in the Ohm’s law simulation.
4.2 Household electrical circuits
Electricity reaches homes through three wires: live (red or brown, high potential), neutral (black or blue, zero potential) and earth (green or yellow, for safety). Fuses and MCBs protect appliances from short circuits and overloading.