Question

An electric heater is rated $1500W$. The energy used by it in $10hours$ is:

• A. $5kWh$
• B. $10kWh$
• C. $15kWh$
• D. $20kWh$

Answer 1

The correct option is C

$15kWh$

Step 1: Given that

$Power\left(P\right)=1500W$

$Timetaken\left(t\right)=10hours$

Step 2: Calculating energy/work used by heater

$$\begin{gathered} Power\left(P\right)=\frac{Workdone\left(W\right)}{Time\left(t\right)} \\ \Rightarrow 1500W=\frac{W}{10hours} \\ \Rightarrow W=15kWh[\because 1kW=1000W] \end{gathered}$$

Hence, the correct answer is option (C) i.e. $15kWh$