Question:
A 100 Ω resistor is connected to a 220 V, 50 Hz ac supply.
(a) What is the rms value of current in the circuit?
(b) What is the net power consumed over a full cycle?
Solution:
Resistance of the resistor, R = 100 Ω
Supply voltage, V = 220 V
Frequency, ν = 50 Hz
(a) The rms value of current in the circuit is given as:
$I=\frac{V}{R}$
$=\frac{220}{100}=2.20 \mathrm{~A}$
(b) The net power consumed over a full cycle is given as:
P = VI
= 220 × 2.2 = 484 W