Subtopic: Sources of power on the farm – human, animal, mechanical, electrical, wind, solar and biomass
Question Statement:
Which of the following statements regarding farm power sources and their utilization characteristics is/are correct?
Options:
(A) A healthy human laborer can continuously deliver approximately 0.1 hp (75 W) of mechanical power over an 8-hour shift.
(B) A pair of medium-sized working bullocks can develop roughly 0.75 to 1.0 hp (550 to 750 W) of continuous drawbar power.
(C) Stationary electric three-phase induction motors achieve operational efficiencies between 80% and 90% with low maintenance requirements.
(D) Solar PV pump controllers utilize Maximum Power Point Tracking (MPPT) algorithms to dynamically optimize electrical power delivery to the pump across varying solar irradiance.
Answer Key:
A, B, C, D
Step-by-Step Solution & Explanation
All four statements represent established benchmarks for agricultural energy sources:
• Adult human sustained output is ~75 W (A is correct).
• A pair of working bullocks yields ~0.75–1.0 hp at normal walking pace (B is correct).
• Electric induction motors operate at 80–90% efficiency (C is correct).
• MPPT maximizes power harvesting under changing solar insolation (D is correct).