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प्रश्न
Which machine will you use to do the following work? Write their type.
To draw water from a well.
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उत्तर
To draw water from a well, we should use a pulley system or wheel-axle.
संबंधित प्रश्न
Fill in the blank:
The useful work done by an actual machine is always ............ than the work done on the machine.
Name six simple machines. Give an example of each machine.
Give a reason for the following.
Machines are able to make our work convenient.
State the kind of lever which always has mechanical advantage less than 1. Draw a labelled diagram of such a lever.
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)?
Define Efficiency
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’.
Simple machines usually exchange a larger force to move a heavy object.
A pair of scissors is a _____ multiplier.
