Concept:
Resistance: The property of electrical materials and electrical instruments that opposes the flow of current through them is called resistance.
It is denoted by R. The SI unit of resistance is the ohm (Ω).
Power: The rate of work done by an electric current is called power. It is denoted by P. The SI unit of power is the watt (W).
Power dissipation (P) is given by:
\(P=VI=\frac{V^2}{R}=I^2R\)
Where V is the potential difference across resistance, I is current flowing and R is resistance.
Calculation:
With R = 50 Ω, and V = 220 V, the power required by the bulb will be:
\(P=\frac{V^2}{R}=\frac{220\times 220}{50}\)
P = 968 W


