Practicing Success
An electric bulb rated 220 v and 60 W is connected in series with another electric bulb rated 220 v and 40 W. The combination is connected across 220 volt source of e.m.f. If Power of bulb 1 is $P_1'$ and power of bulb 2 is $P_2'$ then |
$P_1' > P_2'$ $P_1' < P_2'$ $P_1' = P_2'$ None of the above |
$P_1' < P_2'$ |
$R = \frac{V^2}{P}$ $\text{Resistance of the first bulb } R_1 = \frac{V^2}{P_1}$ $\text{Resistance of the first bulb } R_2 = \frac{V^2}{P_2}$ $\text{In series same current will pass through each bulb}$ $\text{Ratio of Power is }P_1' = I^2\frac{V^2}{P_1} $ $\text{Ratio of Power is }P_2' = I^2\frac{V^2}{P_2} $ $\Rightarrow \frac{P_1'}{P_2'}= \frac{P_2}{P_1} <1$ $\Rightarrow P_1' < P_2'$ |