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प्रश्न
State two reasons, why the efficiency of a pulley system is not 100 percent?
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उत्तर
The two reasons are:
(i) Some effort is used (or wasted) in overcoming the friction between the string and the grooves of the pulleys.
(ii) Some effort is used up (wasted) in lifting up the movable block along with the load.
On account of the above two reasons, effort applied is always more than the load lifted up and so the M.A. is always less than 1. Hence efficiency is always less than 100%.
संबंधित प्रश्न
From the diagram given below. answer the question that follows:
1) What kind of pulleys are A and B?
2) State the purpose of pulley B.
3) What effort has to be applied at C just raise the load L = 20 kgf?
(Neglect the weight of pulley A and friction)
Is the above pulley system an ideal machine or not?
State two functions of a machine.
Answer the following in detail.
How does a pulley make work simpler?
Define the following term in reference to a gear system for Gear ratio ?
The mechanical advantage of an ideal single movable pulley is ______.
Give reason for the following:
The efficiency of a pulley is always less than 100%
Draw the diagram of a single movable pulley and obtain its mechanical advantage, velocity ratio, and efficiency.
Draw a diagram of a single fixed pulley and obtain expressions for its:
(i) Mechanical advantage,
(ii) Velocity ratio, and
(iii) Efficiency, in the ideal case.
The pulley system shown in the figure is to be used to lift a load W. If the man applying the effort cannot apply a force exceeding 1000 N, what is the maximum load that can be lifted?
The actual load that the man is finally able to lift turns out to be 2700 N. What are the values of the actual M.A., obtained, and the efficiency of the actual set-up?
