Question

20 labors engaged in a farm-operation on paddy farm for 6h. In an ideal conditions, how much maximum energy is utilized by labors into the farm?

(A)	8.94 kWh
(B)	120 kWh
(C)	12 hPh
(D)	240 hPh

Choose the correct answer from the options given below:

• A. (A), and (C) only.
• B. (B) and (D) only.
• C. (C) and (D) only.
• D. (B) and (C) only.

Hint:

Take 0.1 hp per laborer, multiply by number of workers and hours, then convert hp-h to kWh to check which pair matches.

Answer 1

The Correct Option is A

Step 1: Under ideal working conditions, the standard rating for continuous human labor is taken as 0.1 hp per person.

Step 2: Total power for 20 laborers is \( 20 \times 0.1 = 2 \, \text{hp} \). Energy used over 6 hours is \( 2 \times 6 = 12 \, \text{hp-h} \), which matches option (C).

Step 3: Converting to kWh using \( 1 \, \text{hp} = 0.746 \, \text{kW} \): \( 12 \times 0.746 = 8.95 \, \text{kWh} \), which rounds to the 8.94 kWh given in option (A). So (A) and (C) represent the same energy value in two different units, and both are correct while (B) and (D) are far too large.