Question

An electric geyser is rated $2000W-220V$. Calculate the monthly bill for running the geyser for $2hours$ daily when energy cost is $₹4perkWh$.

Answer 1

Step 1 - Given data

Power $P=2000W$ or $P=2kW$

(Note: $1kW=1000W$)

Time of consumption of power in one day $t=2h$

Step 2 - Finding the total time for consumption of power in a month

Consider the total time of power consumption in a complete month is $T$.

$$\begin{gathered} T=30\times t \\ T=30\times 2h \\ T=60h \end{gathered}$$

Step 3 - Finding the total energy consumed in a month

Consider the total consumed energy is $E$.

So, the total energy $E$ is given by

$$\begin{gathered} E=P\times t \\ E=(2kW)\times (60h) \\ E=120kWh \end{gathered}$$

Step 4 - Finding the monthly bill for running the geyser

Consider the energy cost is $r$.

The total monthly bill $R$ is

$$\begin{gathered} R=E\times r \\ R=(120kWh)\times (₹4/kWh) \\ R=₹480 \end{gathered}$$

Hence, the monthly bill is $₹480$.