Two electric bulbs , rated for the same voltage , have powers of `200 W and 100 W`, respectively. If their resistances are `r_(1) and r_(2)` , respectively , then

Options

A. ` r_(1) = 2 r_(2)`
B. ` r_(2) = 2 r_(1)`
C. ` r_(2) = 4 r_(1)`
D. ` r_(1) = 4 r_(2)`

Answer

B

Explanation

`P = ( V^(2))/ ( R ) , (P_(1))/( P_(2)) = ( R_(2))/( R_(1)) or r_(2) = 2 r_(1)`