Answer to Question #184377 in Electric Circuits for Jishnu

Question

How much is the power of an appliances of 500hm resistance working with 200v supply

Answer 1

Explanations & Calculations

• The power of a device is basically given by the equation $\small P=Vi$.
• And with the use of the equation $\small V=iR$, another two ways of expressing the same equation can be obtained as $P=\frac{V^2}{R}\qquad P=i^2 R$
• According to the available data, any suitable form should be chosen.

• Knowns — $\small V= 200V$ and $\small R= 50\,\Omega$

• Then using the form: $\small P=\frac{V^2 }{R}$, the power could be found.

$\qquad\qquad \begin{aligned} \small P &=\small \frac{(200V)^2}{50\Omega}\\ &=\small \bold{800\,W} \end{aligned}$