MDCAT Physics MCQ #4428

A machine has an efficiency of 80% and does 400 J of work. What is the input energy to the machine?

MDCAT Physics MCQ #4428

  1. Question 1

    Q1. A machine has an efficiency of 80% and does 400 J of work. What is the input energy to the machine?

    • A) 400 J
    • B) 500 J
    • C) 600 J
    • D) 800 J

    Answer: 500 J

    Explanation: Efficiency = Output / Input; 0.8 = 400 J / Input; Input = 400 J / 0.8 = 500 J. Option A fails due to incorrect efficiency application.