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प्रश्न
Differentiate between a single fixed pulley and a single movable pulley.
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उत्तर
| Single fixed pulley | Single movable pulley |
| 1. It is fixed to a rigid support. | 1. It is not fixed to a rigid support |
| 2. Its mechanical advantage is one . | 2. Its mechanical advantage is two. |
| 3. Its velocity ratio is one. | 3. Its velocity ratio is two. |
| 4. The weight of pulley itself does not affect its mechanical advantage. | 4. The weight of pulley itself reduces its mechanical advantage. |
| 5. It is used to change the direction of effort | 5. It is used as force multiplie |
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
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.
State whether the following statement is True or False.
A pulley changes the direction of force.
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 ?
What should be the gear ration of a car : equal to 1, less than 1 or greater than 1, while ascending a hill ?
What is a single movable pulley? What is its mechanical advantage in the ideal case?
What is the use of a fixed pulley?
(a) Fig represents an incomplete diagram of a simple string pulley system. Copy this diagram on a new page and complete it and mark where the effort must be applied to lift the load.
(b) What is the velocity ratio of this system?
(c) If the pulley system is 80% efficient and the load is 720 N, then
(i) What effort must be applied to lift the load?
(ii) What work must be done must be done in lifting the load through a distance of 2 m using this machine?
Name the type of single pulley that has an ideal mechanical advantage equal to 2. Draw a labelled diagram of the pulley mentioned by you.
