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प्रश्न
Fill in the blank:
The useful work done by an actual machine is always ............ than the work done on the machine.
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उत्तर
The useful work done by an actual machine is always less than the work done on the machine.
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संबंधित प्रश्न
What do you understand by a simple machine?
The correct relationship between the mechanical advantage (M.A.), the velocity ratio (V.R.) and the efficiency (n) is ______.
Give an example of the following uses of a machine:
to obtain gain in speed
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)?
Give an example where a machine is used to obtain gain in speed.
Define mechanical advantage (M.A.) of the machine.
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’.
Classify the following as a lever, a pulley and an inclined plane:
The wheel of a flagpole
Classify the following as a lever, a pulley and an inclined plane:
Nutcrackers
Rearrange the letters and find out the name of the tool.
R L E V E
| ______ | ______ | ______ | ______ |
