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प्रश्न
In which direction does the force need to applied, when a single pulley is used with a mechanical advantage greater than one? How can you change the direction of force applied without altering its mechanical advantage? Draw a labelled diagram of the system.
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उत्तर
A single movable pulley can be used to obtain an M.A. greater than 1, but this is impractical as it requires exerting force in an upward direction. Instead, a fixed pulley is used in conjunction with the movable pulley to apply force in a downward direction.
The only purpose of a fixed single pulley is to shift the force's application direction in a direction that is convenient.
M.A. = `(2T)/T = 2`
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संबंधित प्रश्न
A pulley system has three pulleys. A load of 120 N is overcome by applying an effort of 50N. Calculate the Mechanical Advantage and Efficiency of this system.
Is the above pulley system an ideal machine or not?
Fill in the blank:
A pulley is used to change ........................
Select the correct alternative:
A pulley is used because of it
State two functions of a machine.
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?
Give reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.
Name a machine which is used to:
change the direction of force applied.
A pulley system has a velocity ratio of 4 and an efficiency of 90%. Calculate:
(i) the mechanical advantage of the system.
(ii) the effort required to raise a load of 300 N by the system.
_______ is a machine made up of wheel and rope.
