Work Energy And Power Question 179
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
Options:
A) Rs. 350/-
B) Rs. 358/-
C) Rs. 375/-
D) Rs. 397/-
Show Answer
Answer:
Correct Answer: B
Solution:
If a motor of 12 HP works for 10 days at the rate of 8 hr/day then energy consumption = power × time = $ 12\times 746\frac{J}{\sec }\times (80\times 60\times 60)\ \sec $
$ =12\times 746\times 80\times 60\times 60\ J $ = 2.5 × 109 J
Rate of energy = $ 50\frac{paisa}{kWh} $ i.e. $ 3.6\times 10^{6}J $
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\ Rs $
