Question

A 12 HP motor has to be operated 8 hours/day. How much will it cost at the rate of 50 paisa/kWh in 10 days

• A. Rs. 350/-
• B. Rs. 358/-
• C. Rs. 375/-
• D. Rs. 397/-

Answer 1

Answer: (B)

Rs. 358/-

Answer 2

If a motor of 12 HP works for 10 days at the rate of 8 hr/day then energy consumption = power × time

=

= 2.5 × 10⁹ J

Rate of energy =

i.e. energy cost 0.5 Rs

So 2.5 × 10⁹ J energy cost

= $\frac { 2.5 \times 10 ^ { 9 } } { 2 \times 3.6 \times 10 ^ { 6 } } = 358 \mathrm { Rs }$