Question

The cost at 5 paise per kWh of operating an electric motor for 8 hours, which takes 15 ampere at 110 V, is 11y paise. Calculate y.

Answer 1

Total energy consumed for 8 hours = iVt

= 15 × 110 × 8 × 10^–3 kWh

= 13.2 kWh

Total cost = 5 × 13.2 = 66 paise

11y = 66 

⇒ y = 6