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प्रश्न
Give reason for the following:
The lower block of a block and tackle pulley system must be of negligible weight
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उत्तर
The lower block pulleys should be as light as possible to maximise efficiency, and lubricants should be used to reduce friction in pulley bearings.
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संबंधित प्रश्न
Rohan exerts a pull of 150 kgf. What is the maximum load he can raise with this pulley system if its efficiency = 75%?
Answer the following in short.
Explain the various functions that a machine can perform.
Answer the following in detail.
How does a pulley make work simpler?
Explain the working of a gear system.
Define the following term in reference to a gear system of Driving gear ?
Give a reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.
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?
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.
A boy lifts a load of 40 kgf through a vertical height of 2m in 5s by using a single fixed pulley when he applies an effort of 48 kgf. Calculate:
(i) the mechanical advantage, and
(ii) the efficiency of the pulley. Why is the efficiency of the pulley is not 100%?
(iii) the energy gained by the load in 5s, and
(iv) the power developed by the boy in raising the load.
_______ is a machine made up of wheel and rope.
