Question

A bulb is rated as 250 v; 0.4 A. Find it’s: 1. Power and 2. Resistance

Answer 1

1. Power = V×I= 250×0.4= 100W
2.resistance = V/I= 250/0.4= 625 ohm.

Answer 2

Explanation:

It is given that,

Voltage of bulb, V = 250 volts

Current flowing through bulb, I = 0.4 A

The power of an electrical appliance is the product of voltage and the current i.e.

(1) P = V × I

$P=(250\times 0.4)\ Watts$

$P=100\ Watts$

(2) The Ohm's law gives the relationship between the current, voltage and resistance.

$R=\dfrac{V}{I}$

$R=\dfrac{250}{0.4}$

$R=625\ \Omega$

Hence, this is the required solution.