Question

Two electric bulbs of 50 W and 100 W are given. When they are (i) connected in series (ii) connected in parallel, which bulb will glow more ?

Answer 1

Resistance of a bulb `R = V^(2)//P or R prop1//P`. Thus the resistance of 50 W bulb is more than thtat of 100 W bulb. As glow `prop` power of a bulb.
(i) In series connection, the current is same, so power `=I^(2)R`, i.e., `P prop R`.
`:.` 50 W bulb will glow more than 100 W bulb.
(ii) In parallel connection, power `(P) = V^(2)//R`, i.e., `P prop 1//R`. Thus 100 W bulb will glow more than that of 50 W bulb.