Question

A bulb rating $200W$,$220W$ is used for $6$ hours a day for a month of $30$ days. How many units of electrical energy are consumed by the bulb in one month? If the rate of each unit is Rs.$3.25$, what is the total bill for the month?

Answer 1

Hint:In the question, we have to find the total bill of the month. Firstly, we have to calculate the energy consumed in a day. Then multiply it with the number of days and then multiply it with the rate of the unit. And the question, we are given the rate.

Complete step by step answer:
Energy consumed in one day is given by $ = \dfrac{{200 \times 6}}{{1000}}$ =$1.2kWh$
Energy consumed in a month will be calculated by simply multiplying the per day consumption with the number of days in a month. Hence, energy consumed in a month $ = 1.2 \times 30 = 36kWh$.
According to the question, rate of each unit is Rs. $3.25$.And we have to calculate the total bill of the month. So, we can multiply the energy consumed for a month to the rate of each unit.Hence, multiplying, $3.25 \times 36 = 117$.

So, the total bill of the month is Rs.$117$.

Note:The unit $kWh$ is read as kilo-watt-hour. It is the units of energy commonly used for billing units of energy delivered to the consumers. One kilo-watt-hour when converted to standard units of energy i.e., joules $1kWh = 3200kJ$.