Power and Efficiency of A Machine | Numericals

What is the efficiency of a machine, given mechanical advantage is 2 and velocity ratio is 4?

(i) With reference to the terms, mechanical advantage, velocity ratio and efficiency of a machine, name the term that will not change for a machine of a given design. (ii) Define the term stated by you in part (i).

Efficiency of an ideal machine is _____.

Answer true or false: If the efficiency of a machine is 100%, the mechanical advantage equals the velocity ratio.

A machine rated as 150 W , changes the velocity of a 10 kg mass from 4 ms^(-1) to 10 ms^(-1) in 4s . The efficiency of the machine is nearly.

Incomplete combustion of coal and petroleum: (i) increases air pollution. (ii) increases efficiency of machines. (iii) reduces global warming. (iv) produce poisonous gases.

In a wheel and axle machine the radii of the wheel and axle are 0.5 m and 0.05 m,respectively . A weight of 100 kg is raised when it is hanging by a rope from the axle by applying a force of 12 kg on the circumference of the wheel . Find the mechanical advantage, velocity ratio and efficiency of this machine.