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प्रश्न
State one advantage of single movable pulley.
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उत्तर
A single movable pulley has the advantage of increasing its mechanical advantage by acting as a force multiplier.
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संबंधित प्रश्न
State whether the following statement is True or False.
A pulley changes the direction of force.
Define the following term in reference to a gear system for Gear ratio ?
Define the following term in reference to a gear system for Gain in torque ?
What should be the gear ration of a car : equal to 1, less than 1 or greater than 1, while gaining speed on the road ?
Give two reasons why the efficiency of a single movable pulley system is not 100%.
Draw a diagram of a combination of three movable pulleys and one fixed pulley to lift up a load. In the diagram, show the directions of load, effort and tension in each strand. Find:
- mechanical advantage,
- Velocity ratio and
- efficiency of the combination in ideal situation.
A pulley system has a velocity ratio 3. Draw a diagram showing the point of application and direction of load (L), effort (E) and tension (T). It lifts a load of 150 N by an effort of 60 N. Calculate its mechanical advantage. Is the pulley system ideal? Give reason.
Fig shown a block and tackles system of pulleys used to lift a load.
(i) How many strands of tackle are supporting the load?
(ii) Draw arrows to represent tension in each stand.
(iii) What is the mechanical advantage of the system?
(iv) When load is pulled up by a distance 1 m how far does the effort end move?
(a) Fig represents an incomplete diagram of a simple string pulley system. Copy this diagram on a new page and complete it and mark where the effort must be applied to lift the load.
(b) What is the velocity ratio of this system?
(c) If the pulley system is 80% efficient and the load is 720 N, then
(i) What effort must be applied to lift the load?
(ii) What work must be done must be done in lifting the load through a distance of 2 m using this machine?
