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प्रश्न
A pulley system has three pulleys. A load of 120 N is overcome by applying an effort of 50N. Calculate the Mechanical Advantage and Efficiency of this system.
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उत्तर
Load = 120 N; E = 50 N; n = 3
Mechanical advantage of pulley system is
M.A. = `L/E = 120/50` = 2.4
The efficiency of the system is
`eta = ("M.A.")/("V.R.") = (2.4)/n = 2.4/3 = 0.8 = 80%`
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संबंधित प्रश्न
Fill in the blank:
A pulley is used to change ........................
What is the mechanical advantage of an ideal pulley?
Differentiate between a single fixed pulley and a single movable pulley.
Name the type of single pulley that can act as a force multiplier. Draw a labelled diagram of the pulley mentioned by you.
In which direction does the force need to applied, when a single pulley is used with a mechanical advantage greater than one? How can you change the direction of force applied without altering its mechanical advantage? Draw a labelled diagram of the system.
A block and tackle pulley system has a velocity ratio 5. Draw a labelled diagram of this system. In your diagram, indicate clearly the points of application and the directions of the load and effort.
Give reason for the following:
The efficiency of a pulley is always less than 100%
The alongside figure shows the combination of a movable pulley P1 with a fixed pulley P2 used for lifting up a load W.
(i) State the function of the fixed pulley P2.
(ii) If the free end of the string moves through a distance x, find the distance by which the load W is raised.
(iii) Calculate the force to be applied at C to just raise the load W = 20 kgf, neglecting the weight of the pulley P1 and friction.
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?
A pulley is a machine made up of a ______.
