Question

A radio set of 60 W runs for 60 hours. How much electrical energy is consumed?

Answer 1

Step 1. Given data

Power of the radio, $P=60W$

Running time, $t=60h$,

Step 2. Find the electrical energy

$\mathit{E}\mathit{l}\mathit{e}\mathit{c}\mathit{t}\mathit{r}\mathit{i}\mathit{c}\mathit{a}\mathit{l}\mathbf{}\mathit{e}\mathit{n}\mathit{e}\mathit{r}\mathit{g}\mathit{y}\mathbf{\left(}\mathbf{E}\mathbf{\right)}\mathbf{=}\mathit{P}\mathit{o}\mathit{w}\mathit{e}\mathit{r}\mathbf{}\mathbf{\left(}\mathbf{P}\mathbf{\right)}\mathbf{\times }\mathit{T}\mathit{i}\mathit{m}\mathit{e}\mathbf{\left(}\mathbf{t}\mathbf{\right)}$

Substitute the given values into the formula,

$E=60W\times 60h$

$E=3600Wh$

Let's convert $Wh$ to $kWh$,

As we know $1kW$ is equal to $1000W$,

Therefore, the value of electrical energy is $\mathit{E}\mathbf{=}\mathbf{3600}\mathit{W}\mathit{h}\mathbf{=}\mathbf{3}\mathbf{.}\mathbf{6}\mathbf{}\mathit{k}\mathit{W}\mathit{h}$.