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प्रश्न
Write two uses of pulleys. Is pulley a force multiplier?
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उत्तर
Two uses of pulley:
(i) To change the direction of application of force to a convenient direction.
(ii) To multiply force.
Yes, a pulley is a force multiplier
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संबंधित प्रश्न
A boy uses a single fixed pulley to lift a load of 50 kgf to some height. Another boy uses a single movable pulley to lift the same load to the same height. Compare the effort applied by them. Give a reason to support your answer.
The mechanical advantage of an actual pulley is less than one. Give a reason. What is the justification for using the pulley then?
State if the following statement is true or false. Correct the statement if it is false.
A single movable pulley is a pulley that has its axis of rotation fixed.
Explain how a gear system can be used to obtain gain in speed? Given one example.
Define the following term in reference to a gear system for Gain in torque ?
Name the type of single pulley that can act as a force multiplier. Draw a labelled diagram of the pulley mentioned by you.
Give two reasons why the efficiency of a single movable pulley system is not 100%.
The diagram below shows a pulley arrangement :
(i) Copy the diagram and mark the direction of tension on each strand of the string.
(ii) What is the velocity ratio of the arrangement ?
(iii) If the tension acting on the string is T, then what is the relationship between T and effort E ?
(iv) If the free end of the string moves through distance x, find the distance by which the load is raised.
What is a block and tackle system of pulleys? What precautions would you observe while rounding the string so that the effort is applied in the downward direction?
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)
