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Current Electricity

Question

Two electric bulbs P and Q have their resistances in the ratio of 1: 2. They are connected in series across a battery.Find the ratio of the power dissipation in these bulbs.

Solution

Let ratio be x

R_p = x (Resistance of bulb P)

R_q = 2x (Resistance of bulb Q)

We know, P = VI = V.V/R

$\frac{P_{p}}{P_{q}} = \frac{V_{2}}{R_{p}} x \frac{R_{q}}{V_{2}} (In series Potential will be same) \frac{P_{p}}{P_{q}} = \frac{2 x}{x} 2 : 1$