Question

An electric heater generates 3*10⁴ J of heat when it is allowed to workcontinuously for 20 minutes. The resistance of heater element is 100 OHM . What is potential difference developedacross the heater?

Answer 1

Dear Student,

$$\begin{gathered} H=3\times {10}^{4}J \\ t=20min=20\times 60sec \\ R=100ohm \\ H=I^2\times R\times t \\ 3\times {10}^4=I^2\times 100\times 20\times 60 \\ {I}^2=\frac{3\times {10}^4}{100\times 20\times 60}=0.25A \\ I=\sqrt{0.25}=0.5A \\ V=IR \\ V=0.5\times 100=50V \end{gathered}$$

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