Question

Calculate the electrical energy consumed when a bulb of $40W$ is used for $12.5hours$ every day for 30 days.

Answer 1

Step 1: Given data

Power $P=40W$

time $t=12.5h\times 30days=375h$

Step 2: To find out the energy consumed

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

$$\begin{gathered} \Rightarrow H=P\times t \\ \Rightarrow H=40\times 375W-h \\ \Rightarrow H=\frac{40\times 375}{1000}kW-h \\ \Rightarrow H=15kW-h \end{gathered}$$

Hence, the energy consumed by the bulb is $H=15kW-h$.