There are two electric bulbs of `40 W` and `100 W`. Which one will be brighter when first connected in series and then in parallel ?

Options

A. `40 W` in series and `100 W` in parallel
B. `100 W` in series and `40 W` in parallel
C. `40 W` both in series and parallel will be uniform
D. `100 W` both in series and parallel will be uniform

Answer

A

Explanation

(a) `(R_(1))/(R_(2)) = (P_(2))/(P_(1)) = (100)/(40) = (5)/(2)`
Resistance of `40 W` bulb is `(5)/(2)`
time than `100 W`. In series, `P = i^(2) R` and in parallel,
`P = (V^(2))/(R )` So `40 W` in series and `100 W` in parallel will grow brighter.