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प्रश्न
A machine is 75% efficient’. What do you understand by this statement?
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उत्तर
If a machine is 75% efficient, it means that 75% of the work input to the machine is obtained as the useful work output. The remaining 25% of the work input has been lost in overcoming the friction.
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संबंधित प्रश्न
What is the principle on which a machine works?
Derive the relationship between mechanical advantage, velocity ratio and efficiency of a machine.
Fig show a system of four pulleys. The upper two pulleys are fixed and the lower two are movable.
(i) Draw a string around the pulleys. Also show the place and direction in which the effort is applied.
(ii) What is the velocity ratio of the system?
(iii) What is the mechanical advantage of the system?
(iv) What assumption do you make in arriving at your answer in part (iii)?
Classify the following as a lever, a pulley and an inclined plane:
A wedge
Classify the following as a lever, a pulley and an inclined plane:
A slide
Classify the following as a lever, a pulley and an inclined plane:
An opener
The ______ in the centre, the ______ on one side and the ______ on the other side make a lever of the second order.
Which machine will you use to do the following work? Write their type.
To hold a papad for roasting it.
What is meant by simple machines?
______ help us to make work easier.
