A heater A gives out 300 W of heat when conn | vedclass

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(D) The power of a heater is given by $P = \frac{V^2}{R}$,where $V$ is the voltage and $R$ is the resistance.For heater $A$: $R_A = \frac{V^2}{P_A} =

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$200$

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(D) The power of a heater is given by $P = \frac{V^2}{R}$,where $V$ is the voltage and $R$ is the resistance.For heater $A$: $R_A = \frac{V^2}{P_A} = \frac{200^2}{300} = \frac{40000}{300} = \frac{400}{3} \ \Omega$.For heater $B$: $R_B = \frac{V^2}{P_B} = \frac{200^2}{600} = \frac{40000}{600} = \frac{400}{6} = \frac{200}{3} \ \Omega$.When connected in series,the equivalent resistance is $R_{eq} = R_A + R_B = \frac{400}{3} + \frac{200}{3} = \frac{600}{3} = 200 \ \Omega$.The new power output $P_{eq}$ when connected to the same $200 \ V$ supply is $P_{eq} = \frac{V^2}{R_{eq}} = \frac{200^2}{200} = \frac{40000}{200} = 200 \ W$.

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