Correct AnswerA. Efficiency of LED bulb is greater than efficiency of CFL bulb
Quick Explanation
For comparable useful light output, LED lamps generally have higher luminous efficacy than CFL lamps and far higher efficacy than incandescent lamps. Therefore the statement that LED efficiency is greater than CFL efficiency is correct: option A.
Detailed Explanation
Correct Answer
A — Efficiency of LED bulb is greater than efficiency of CFL bulb
Concept and Reasoning
For comparable useful light output, LED lamps generally have higher luminous efficacy than CFL lamps and far higher efficacy than incandescent lamps. Therefore the statement that LED efficiency is greater than CFL efficiency is correct: option A.
Calculation / Key Relation
Luminous efficacy = luminous flux (lm) / electrical power (W)
Exam Takeaway
Modern lighting efficiency order: LED generally exceeds CFL, which exceeds incandescent.
Common Mistake
Compare lamps on useful light output per watt, not only on rated wattage.
