Question

A geyser has a label of 2kW-240 V. What is the cost of using it for 30 minutes if the cost of electricity is ₹ 3.00 per commercial unit?

Answer 1

Step 1- Given data

Power input, $P=2kW=2000W$

Voltage difference, $V=240V.$

Rate per unit $r=₹3perkW-h.$

Time $t=30minutes=\frac{30}{60}=0.5h.$

Step 2- To find out the energy consumed-

The formula for the current in the circuit is $H=P\times t$

$$\begin{gathered} \Rightarrow H=P\times t \\ \Rightarrow H=\left(2000\right)\times 0.5W-h. \\ \Rightarrow H=\frac{\left(2000\right)\times 0.5}{1000}=1kW-h. \end{gathered}$$

Thus, the energy consumed in $0.5hours$is $1kW-h.$

Step 3- To find out the cost of electrical energy consumed-

The formula for the cost will be $=r\times H$

$$\begin{gathered} \Rightarrow \cos t=r\times H \\ \Rightarrow \cos t=₹3\times 1 \\ \Rightarrow \cos t=₹3 \end{gathered}$$

Thus, the cost of using a geyser is $₹3$.