Question

An electric oven with a resistance of 20 Ω draws a current of 10 A. It works 3 hours daily. Calculate the weekly bill when energy costs ₹ 1.50 per kWh. [Hint (P = I².R)]

Answer 1

Power of oven \[P = I^{2} . R\] \[= (10)^{2} \times 20\] \[= 2000 \text{ W}\]

Energy consumed by oven in a day \[= 2000 \text{ W} \times 3 \text{ h}\] \[= 6000 \text{ Wh}\] \[= 6 \text{ kWh}\]

Energy consumed by oven in 7 days (week) \[= 6 \text{ kWh} \times 7\] \[= 42 \text{ kWh}\]

Weekly bill \[= 42 \text{ kWh} \times \frac{₹ 1.50}{\text{ kWh}}\] \[= \text{₹ 63}\]