Question

A lamp consumes $1000\mathrm{J}$ of electrical energy in $10\mathrm{s}$. What is its power?

Answer 1

Determine the power of the lamp

It is given that the lamp consumes $1000\mathrm{J}$ of electrical energy in $10\mathrm{s}$.

Thus, consumed energy, $E=1000\mathrm{J}$.

The time taken, $t=10\mathrm{s}$.

Therefore, the power, $P=\frac{E}{t}$.

$$\begin{gathered} \Rightarrow P=\frac{1000\mathrm{J}}{10\mathrm{s}} \\ \Rightarrow P=100\mathrm{W} \end{gathered}$$

Hence, the power of the lamp is $100\mathrm{W}$.