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प्रश्न
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.
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उत्तर
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%.`
संबंधित प्रश्न
Fill in the blank:
A pulley is used to change ........................
State two functions of a machine.
Explain how a gear system can be used to obtain gain in torque? Given one example.
The diagram below shows a pulley arrangement.
- Name the pulleys A and B.
- In the diagram, mark the direction of tension on each strand of string.
- What is the purpose of the pulley B?
- If the tension is T, deduce the relation between
- T and E, and
- E and L.
- What is the velocity ratio of the arrangement?
- Assuming that the efficiency of the system is 100%, what is the mechanical advantage?
What is a block and tackle system of pulleys?
Give reason for the following:
The efficiency of a pulley is always less than 100%
Write two uses of pulleys. Is pulley a force multiplier?
Draw the diagram of a single movable pulley and obtain its mechanical advantage, velocity ratio, and efficiency.
_______ is a machine made up of wheel and rope.
A block and tackle system of pulleys has a velocity ratio of 4.
- Draw a labelled diagram of the system indicating clearly the direction of the load and effort.
- Calculate the potential energy of the load 100 kgf lifted by this pulley to a height 5 m. (g = 10 ms−2)
