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.
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%.`
APPEARS IN
RELATED QUESTIONS
A block and tackle system has V.R. = 5.
Draw a neat labeled diagram of a system indicating the direction of its load and effort
Explain the working of a gear system.
What should be the gear ration of a car : equal to 1, less than 1 or greater than 1, while gaining speed on the road ?
Give two reasons why the efficiency of a single movable pulley system is not 100%.
A block and tackle pulley system has a velocity ratio 5. Draw a labelled diagram of this system. In your diagram, indicate clearly the points of application and the directions of the load and effort.
Name the type of single pulley that can act as a force multiplier. Draw a labeled diagram of the pulley mentioned by you.
Give reason for the following:
In case of a block and tackle system, the mechanical advantage increases with the increase in the number of pulleys.
In the case of a block and tackle arrangement, the mechanical advantage increases with the number of pulleys. Explain.
The alongside figure shows the combination of a movable pulley P1 with a fixed pulley P2 used for lifting up a load W.
(i) State the function of the fixed pulley P2.
(ii) If the free end of the string moves through a distance x, find the distance by which the load W is raised.
(iii) Calculate the force to be applied at C to just raise the load W = 20 kgf, neglecting the weight of the pulley P1 and friction.
A block and tackle system of pulleys has a velocity ratio of 4.
- Draw a labelled diagram of the system indicating clearly the points of application and directions of load and effort.
- What is the value of the mechanical advantage of the given pulley system if it is an ideal pulley system?
