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प्रश्न
What is the mechanical advantage of an ideal pulley?
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उत्तर
In an ideal pulley, the effort applied is equal to the load to be lifted.
i.e. Effort = Load
Mechanical advantage = Load / Effort = 1
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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
Draw a neat labelled diagram showing a pulley being used to lift a load. How are load and effort related in an ideal situation?
Explain how a gear system can be used to obtain gain in torque? Given one example.
Give two reasons why the efficiency of a single movable pulley system is not 100%.
Differentiate between a single fixed pulley and a single movable pulley.
Draw a diagram of a combination of three movable pulleys and one fixed pulley to lift up a load. In the diagram, show the directions of load, effort and tension in each strand. Find:
- mechanical advantage,
- Velocity ratio and
- efficiency of the combination in ideal situation.
Fig shown a block and tackles system of pulleys used to lift a load.
(i) How many strands of tackle are supporting the load?
(ii) Draw arrows to represent tension in each stand.
(iii) What is the mechanical advantage of the system?
(iv) When load is pulled up by a distance 1 m how far does the effort end move?
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?
_______ is a machine made up of wheel and rope.
| Meera chose to use a block and tackle system of '9' pulleys instead of a single movable pulley to lift a heavy load. |
Why should she connect more number of pulleys in the upper fixed block?
