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प्रश्न
Fill in the blank:
A pulley is used to change ........................
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उत्तर
A pulley is used to change the direction of effort.
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संबंधित प्रश्न
Is the above pulley system an ideal machine or not?
What is the justification for using the pulley then ?
Explain how a gear system can be used to obtain gain in torque? Given one example.
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.
The mechanical advantage of an ideal single movable pulley is ______.
State two reasons, why the efficiency of a pulley system is not 100 percent?
Draw the diagram of a single movable pulley and obtain its mechanical advantage, velocity ratio, and efficiency.
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?
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 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:
(i) the mechanical advantage, and
(ii) the efficiency of the pulley. Why is the efficiency of the pulley is not 100%?
(iii) the energy gained by the load in 5s, and
(iv) the power developed by the boy in raising the load.
