Advertisements
Advertisements
Question
In a single movable pulley system, a load of 125 kgf is lifted by an effort of 75 kgf. Find the percentage efficiency of system.
Advertisements
Solution
V.R. of single movable pulley = No. of supporting segments of string = 2
M.A. of single movable pulley =`"L"/"E"=125/75=5/3`
% efficiency =`"M.A."/"V.R."xx100`
= `(5xx100)/(3xx2)=83%.`
RELATED QUESTIONS
Rohan exerts a pull of 150 kgf. What is the maximum load he can raise with this pulley system if its efficiency = 75%?
Fill in the blank:
A pulley is used to change ........................
Solve the following numerical problem.
What effort will be required to lift a load of 500 N by a single movable pulley? [Hint: Mechanical advantage of a single movable pulley is two].
Explain how a gear system can be used to obtain gain in torque? Given one example.
Name the type of single pulley that can act as a force multiplier. Draw a labeled diagram of the pulley mentioned by you.
Give a reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.
Write two uses of pulleys. Is pulley a force multiplier?
State two reasons, why the efficiency of a pulley system is not 100 percent?
A man raises a load of 360 kgf using a block and tackle system of 3 pulleys. If the efficiency of the pulley system is 60%, what effort is applied by the man?
