Question

An electrical bulb rated 220 V, 100 W, is connected in series with another bulb rated 220 V, 60 W. If the voltage across combination is 220 V, the power consumed by the 100 W bulb will be about ____ W.

Answer 1

The correct answer is $14W$
$R_1=\frac{(220)^2}{100}=484 Ω$, $R_2=\frac{(220)^2}{60}=\frac{48400}{60} Ω$
Current (i) 1=$\frac{220}{484\frac{4840}{6}}=\frac{15}{88}amp$
$P_1=\left (\frac{15}{88}\right)^2×484=14.06W=14W$