Question

In India electricity is supplied for domestic use at 220 V. It is supplied at 110 V in USA. If the resistance of a 60W bulb for use in India is R, The resistance of a 60W bulb for use in USA will be :-

Answer 1

$\huge\mathfrak\pink{Hello}$

R/4 is the answer.

Explanation.

The power dissipation of the bulb is written as:
P= V^2 / R 
we have same P for different values of V, so R will also be different for both cases. 
For India:
P = V^2 / R 
it means:
R = V^2/P = 220^2 / 60 = 806.66
now for USA
R = V^2 / R = 110^2 / 60 = 201.667
Comparing these two values we get that R of bulb in USA is 4 times less than those in India. so R/4 is the correct answer. 

$<marquee>THANKS❤❤$