Question

For a heater rated at 4wk and 220v
calculate :- the resistance, energy consumed in 2 hours​

Answer 1

Answer:

$power = 4kw = 4000w \\ potential \: difference = 220v \\ power = \frac{ {v}^{2} }{r} \\ 4000 = \frac{{220}^{2} }{r} \\ r = \frac{220 \times 220}{4000} \\ r = \frac{121}{10} \\ r = 12.1 \\ energy \: consumed = \frac{ {v}^{2} }{r} \times t \\ \frac{220 \times 220}{12.1} \times 4 \\ = 16000wh \\ = 16kwhr$