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प्रश्न
State whether the following statement is True or False.
A pulley changes the direction of force.
विकल्प
True
False
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उत्तर
True.
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संबंधित प्रश्न
Answer the following in short.
Explain the various functions that a machine can perform.
Explain how a gear system can be used to obtain gain in torque? Given one example.
What is the use of a fixed pulley?
Name a machine which is used to:
change the direction of force applied.
There is no gain in mechanical advantage in the case of a single fixed pulley. Explain, why the pulley is then used?
State two reasons, why the efficiency of a pulley system is not 100 percent?
What is the relation between the mechanical advantage and the number of strands of string used to support the load, in a ‘block and tackle’ set-up?
A man raises a load of 360 kgf using a block and tackle system of 3 pulleys. If the efficiency of the pulley system is 60%, what effort is applied by the man?
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.
| 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?
