Question

The power developed in an unknown resistance R is same as power developed across the resistance 8ohm if they separately connected to the battery of internal resistance 4ohm then value of R

Answer 1

first we need to find the current folwing in each case.

in case 1

i=e/r+R

=e/12

in case 2

i=e/4+R

now as power developed us same

p1=p2

V*e/12=V*e/4+r

r=12-4

=8ohms