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प्रश्न
In the alongside the figure of two pulleys shown a system in which one pulley is fixed and the other is movable. What is the velocity ratio of the system?
An effort of 600 N is needed to lift a weight of 1000 N. What are the mechanical advantage and efficiency of the pulley system?
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उत्तर
If there are n movable pulleys connected to a fixed pulley, then the velocity ratio is
V.R = 2n
Velocity ratio of the system = 2.
Mechanical Advantage = `"Load"/"Effort"=1000/600`
=`5/3`
Efficiency = `"M.A."/"V.R."`
= `(5//3)/2=5/(3xx2)=5/6`
= 83.3%.
संबंधित प्रश्न
Is the above pulley system an ideal machine or not?
What is the justification for using the pulley then ?
Draw a neat labelled diagram showing a pulley being used to lift a load. How are load and effort related in an ideal situation?
What is a gear system ?
Explain how a gear system can be used to obtain gain in torque? Given one example.
Define the following term in reference to a gear system for Driven gear ?
The diagram below shows an arrangement of three pulleys A, B, and C. The load is marked as L and the effort as E.
- Name the Pulleys A, B, and C.
- Mark in the diagram the directions of load (L), effort (E) and tension T1 and T2 in the two strings.
- How are the magnitudes of L and E related to the tension T1?
- Calculate the mechanical advantage and velocity ratio of the arrangement.
- What assumptions have you made in parts (c) and (d)?
Give reason for the following:
In case of a block and tackle arrangement, the mechanical advantage increases with the increase in the number of pulleys.
Name the type of single pulley that can act as a force multiplier. Draw a labeled diagram of the pulley mentioned by you.
State two reasons, why the efficiency of a pulley system is not 100 percent?
