Why is the mechanical efficiency of a real gearbox always less than 100 percent?
Pick an answer
Correct!
Not quite. The correct answer is highlighted.
Correct answer to question 126 (Mechanical Comprehension): some input energy is lost to friction and heat
Method
No real machine is perfectly frictionless, so some input energy always converts to heat instead of useful output, keeping efficiency under 100 percent.
Updated: November 2026
Raise your AFQT scoreFree for iPhone and Android
