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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
उत्तर
equal to unity
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संबंधित प्रश्न
The diagram below shows a wheel barrow. Mark position of fulcrum F and draw arrows to show the directions of load L and effort E. What class of lever is the whell barrow? Give one more example of the same class of lever.
State whether the mechanical advantage of an inclined plane is equal to 1, less than 2 or greater than 1?
What is an ideal machine?
Give scientific reason for the following:
Passengers in a bus are pushed backward when it starts suddenly.
A cook used a ‘fire tong pair’ of length 32 cm. to lift a piece of burning coal of mass 500 g. If he applies his effort at a distance of 8 cm from the fulcrum, what is his effort? Assume friction etc. to be absent. Also, obtain values of the M.A. and the V.R. of this ‘machine’.
A simple machine enables us to lift a load of 10,000 N by the application of an effort of 500 N. However, when the point of application of the effort moves through 2.5 m, the load gets raised through 10 cm only. What are the values of the:
(i) M.A.
(ii) V.R. and
(iii) Efficiency of the machine?
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 knife
Which machine will you use to do the following work? Write their type.
To cut vegetables.
The idea of a simple machine originated with the Greek philosopher Archimedes.
