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प्रश्न
A block and tackle system of pulleys has a velocity ratio of 4.
- Draw a labelled diagram of the system indicating clearly the points of application and directions of load and effort.
- What is the value of the mechanical advantage of the given pulley system if it is an ideal pulley system?
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उत्तर
(a)
(b) M. A. = `"Load"/"Efforts" = (4"T"_"L")/"T"_"E" = 4`
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संबंधित प्रश्न
From the diagram given below. answer the question that follows:
1) What kind of pulleys are A and B?
2) State the purpose of pulley B.
3) What effort has to be applied at C just raise the load L = 20 kgf?
(Neglect the weight of pulley A and friction)
State whether the following statement is True or False.
A pulley changes the direction of force.
Fill in the blank:
A pulley is used to change ........................
State two functions of a machine.
Name a machine to change the direction of force ?
Give reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.
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.
Diagram given below shows an arrangement of four pulleys. A load L is attached to the movable lower block and effort E is applied at the free end of the string.
Copy the diagram; and
(i) Draw arrows to indicate tension in each part of the string; and
(ii) Calculate the mechanical advantage of the system.
If the weight of the movable pulley is W, obtain the expression for MA, VR, and efficiency.
A ‘block and tackle’ system used 3 pulleys in the lower block and 4 pulleys in the upper block. What is the ‘velocity ratio’ of this system? If the load is to be lifted by a person capable of applying a maximum effort of 1000 N, what is the maximum load than can be lifted under ideal conditions?
The actual maximum load that gets lifted turns out to be 6300 N. What are the values of the actual M.A. and efficiency of the set-up?
