Question

An electric bulb draws a current of 0.8 A and works on 250 V on an average 8 hours a day. If energy costs ₹ 1.50 per board of trade unit, calculate the monthly bill.

Answer 1

Power of bulb \[P = V I\] \[= 250 \times 0.8\] \[= 200 \text{ W}\]

Energy consumed by bulb in a day \[= 200 \text{ W} \times 8 \text{ h}\] \[= 1600 \text{ Wh}\] \[= 1.6 \text{ kWh}\]

Energy consumed by bulb in 30 days (month) \[= 1.6 \text{ kWh} \times 30\] \[= 48 \text{ kWh}\]

Monthly bill \[= 48 \text{ kWh} \times \frac{₹ 1.50}{\text{ kWh}}\] \[= \text{₹ 72}\]