The efficiency of a machine is always less than 100% because the
- work output is always greater than the work input
- load lifted is always greater than the effort applied
- effort applied is always greater than the load lifted
-
velocity ratio is always greater than the mechanical advantage
The correct answer is: D
Explanation
In real-world machines, due to factors such as friction, deformation, and other losses, the mechanical advantage is always less than the velocity ratio:
MA < VR
This means that the work output (useful work done) is always less than the work input (energy supplied), leading to efficiency being less than 100%.
There is an explanation video available .