Question

10 labors engaged in a farm-operation on paddy farm for 6h. In an ideal condition, how much maximum energy is utilized by labors into the farm?
(A) 4.470 kWh (B) 0.745 Wh (C) 1.0 hph (D) 6.0 hph
Choose the correct answer from the options given below:

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

Hint:

Convert one labourer's power output and multiply by labour-count and duration; check unit equivalence.

Answer 1

The Correct Option is C

Taking the standard rate of manual human labour as roughly 0.0745 kW, or about 0.1 horsepower, the energy delivered by 10 labourers working for 6 hours works out to \(10 \times 0.0745 \times 6 = 4.47\) kWh, matching option (A).
The same amount of work expressed in horsepower-hour units comes to \(10 \times 0.1 \times 6 = 6.0\) hph, matching option (D). These two figures are simply the same physical quantity of energy written in two different units.
Options (B) and (C) don't correspond to this calculation at all, so (A) and (D) together are correct, matching option 3.