Q 12-03-274JEE MainJEE Main 2019 (12 Jan, Shift 1)Easy
Two electric bulbs, rated at $(25\ \text{W}, 220\ \text{V})$ and $(100\ \text{W}, 220\ \text{V})$, are connected in series across a $220$ V voltage source. If the $25$ W and $100$ W bulbs draw powers $P_1$ and $P_2$ respectively, then:
Answer: (D) $P_1 = 16$ W, $P_2 = 4$ W
$R_1 = \dfrac{220^2}{25} = 1936\ \Omega$, $R_2 = \dfrac{220^2}{100} = 484\ \Omega$. In series:
$$I = \frac{220}{2420} = \frac1{11}\ \text{A}$$
$$P_1 = I^2R_1 = \frac{1936}{121} = 16\ \text{W},\qquad P_2 = \frac{484}{121} = 4\ \text{W}$$
Solution by Sreeraj P, M.Sc Physics