Question

an electric bulb of R=500ohm draws current of 0.4A Calculate power of bulb.​

Answer 1

Answer:

P= V2/R

V=IR

= 500×0.4

= 200V

therefore

P= 200×200 /500

= 80W

or 80 watt

Answer 2

$power = i {}^{2} r \\ = 0.4 {}^{2} \times 500 \\ = 4 \times 4 \times 5 = 80 \: watts$