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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 pulley system with VR = 4 is used to lift a load of 175 kgf through a vertical height of 15 m. The effort required is 50 kgf in the downward direction. (g = 10 N kg-1)
Calculate:
- Distance moved by the effort
- Work done by the effort
- M.A. of the pulley system
- Efficiency of the pulley system
Differentiate between a single fixed pulley and a single movable pulley.
What should be the gear ration of a car : equal to 1, less than 1 or greater than 1, while ascending a hill ?
Give two reasons why the efficiency of a single movable pulley system is not 100%.
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?
Differentiate between a single fixed pulley and a single movable pulley.
State two reasons, why the efficiency of a pulley system is not 100 percent?
A type of single pulley is very often used as a machine even though it does not give any gain in mechanical advantage. Name the type of pulley used.
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?
In the alongside the figure of two pulleys shown a system in which one pulley is fixed and the other is movable. What is the velocity ratio of the system?
An effort of 600 N is needed to lift a weight of 1000 N. What are the mechanical advantage and efficiency of the pulley system?
