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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)
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उत्तर
1) The pulley A is a single movable pulley and B is a single fixed pulley.
2) Pulley B is a single fixed type pulley. Its purpose is to change the direction of the effort applied.
3) The effort at C is equal to the load. This is because B is a single fixed pulley and its mechanical advantage is 1. So, we have
M.A. = L/E = 1
∴ E = L = 20 kgf
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संबंधित प्रश्न
State whether the following statement is True or False.
A pulley changes the direction of force.
Draw a neat labelled diagram showing a pulley being used to lift a load. How are load and effort related in an ideal situation?
Solve the following numerical problem.
What effort will be required to lift a load of 500 N by a single movable pulley? [Hint: Mechanical advantage of a single movable pulley is two].
Explain how a gear system can be used to obtain Change in direction of rotation. Given one example.
Give two reasons why the efficiency of a single movable pulley system is not 100%.
Give reason for the following:
In case of a block and tackle system, the mechanical advantage increases with the increase in the number of pulleys.
Draw a diagram of a single fixed pulley and obtain expressions for its:
(i) Mechanical advantage,
(ii) Velocity ratio, and
(iii) Efficiency, in the ideal case.
Draw a diagram showing a block and tackle system of 4 pulleys.
(i) State, how many strands of tackle support the load?
(ii) Draw arrows to represent tension in each strand.
(iii) Find the mechanical advantage of the system, stating the assumptions made.
(iv) If the load is pulled up by a distance 1m, how much does the effort end move?
If the weight of the movable pulley is W, obtain the expression for MA, VR, and efficiency.
