Question

A bulb is rated 40w 220v find the current drawn by it when it is connected to a 220v supply. Also find its resistance.if the given bulb is replaced by a bulb of rating 25w 220v will there be any change in the value of current and resistance justify your answer and determine the change.

Answer 1

HELLO DEAR FRIEND

GIVEN POWER OF BULB = 40w

P. D. = 220v

$\large{ \frac{ {v}^{2} }{r} = 40}$

$\large{ \frac{220 \times 220}{r} = 40 }$

R = 1210 ohm

V = IR

220 = I × 1210

$\huge{ I = \frac{220}{1210} }$

$\huge \boxed{0.8A \: }$