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प्रश्न
Select the correct alternative:
For an ideal machine, the efficiency is
पर्याय
greater than unity
less than unity
equal to unity
depends on the value of load
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उत्तर
equal to unity
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संबंधित प्रश्न
Answer the following in short.
Mention any two methods by which we can take care of machines.
Derive the relationship between mechanical advantage, velocity ratio and efficiency of a machine.
Fig. shows a spade. It is being used to lift soil weighing 30N from the ground.
(a) Mark the direction of the least force on the handle necessary to keep the spade balanced.
(b) Calculate the least force on the handle necessary to keep the spade balanced (the weight of the spade is negligible).
(c) If the left hand was move towards the soil on the spade, would the force on the handle necessary to keep the soil balance the greater or less? Give a reason for your answer.
(d) To which class of lever does the spade belong?
What is the efficiency of an ideal machine?
Write an expression for the mechanical advantage of an inclined plane.
What is the efficiency of a machine?
Classify the following as a lever, a pulley and an inclined plane:
A slide
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 lift bricks to the top of a tall building.
Which machine will you use to do the following work? Write their type.
To cut vegetables.
