A. Efficiency of a machine is always greater than 1
B. Efficiency decreases with an increase in friction
C. Velocity ratio depends on friction
D. Mechanical advantage increases with an increase in friction
Correct Answer:
Option B – Efficiency decreases with an increase in friction

![A load of mass 120kg is raised vertically through a height of 2m in 30s by a machine whose efficiency is 100%. Calculate the power generated by the machine. [g = 10ms‾²] A load of mass 120kg is raised vertically through a height of 2m in 30s by a machine whose efficiency is 100%. Calculate the power generated by the machine. [g = 10ms‾²]](https://erudites.ng/wp-content/plugins/contextual-related-posts/default.png)