A wheel and an axle is used to raise a load whose weight is 800N when an effort of 250N is applied. If the radii of the wheel and axle are 800mm and 200mm respectively, the efficiency of the machine is by Sunday | Nov 7 | Physics JAMB | 0 comments A. 90% B. 80% C. 85% D. 87% Correct Answer: Option B – 80% Users Also Read These:A wheel and axle of radii 800mm and 200mm…A machine of efficiency 80% is used to lift a box.…A simple machine with an efficiency of 75% lifts a…In an ideal wheel an axle system; R stand for the…A machine whose efficiency is 60% has a velocity…