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प्रश्न
Rohan exerts a pull of 150 kgf. What is the maximum load he can raise with this pulley system if its efficiency = 75%?
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उत्तर
Given that
Velocity ratio, VR = 5
Effort = 150 kgf
Efficiency = 75%
We know that efficiency, `eta = "Mechanical Advantage"/"Velocity Ratio"`
`75/100 = "MA"/5`
`Ma = 5 xx 75/100`
∴ Mechanical advantage = 3.75
But, Mechanical advantage = `"Load(L)"/"Effort(E)"`
∴ Load = Mechanical advantage x Effort
= 3.75 x 150 Kgf
= 562.5 Kgf
Therefore, Rohan can raise a maximum load of 562.5 kgf with this pulley system
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संबंधित प्रश्न
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The diagram below shows an arrangement of three pulleys A, B, and C. The load is marked as L and the effort as E.
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- 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?
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- What assumptions have you made in parts (c) and (d)?

Name a machine which is used to:
change the direction of force applied.
What is the relation between the mechanical advantage and the number of strands of string used to support the load, in a ‘block and tackle’ set-up?
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- Draw a labelled diagram of the system indicating clearly the points of application and directions of load and effort.
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A boy lifts a load of 40 kgf through a vertical height of 2m in 5s by using a single fixed pulley when he applies an effort of 48 kgf. Calculate:
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(iii) the energy gained by the load in 5s, and
(iv) the power developed by the boy in raising the load.
