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प्रश्न
Give a reason for the following:
In a single fixed pulley, the velocity ratio is always more than the mechanical advantage.
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उत्तर
In a single fixed pulley, some effort is wasted in overcoming friction between the strings and the grooves of the pulley; so the effort needed is greater than the load and hence the mechanical advantage is less than the velocity ratio.
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)
A block and tackle system has V.R. = 5.
Draw a neat labeled diagram of a system indicating the direction of its load and effort
The mechanical advantage of an actual pulley is less than one. Give a reason. What is the justification for using the pulley then?
Draw a neat labelled diagram showing a pulley being used to lift a load. How are load and effort related in an ideal situation?
What should be the gear ration of a car : equal to 1, less than 1 or greater than 1, while ascending a hill ?
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:
In case of a block and tackle system, the mechanical advantage increases with the increase in the number of pulleys.
There is no gain in mechanical advantage in the case of a single fixed pulley. Explain, why the pulley is then used?
A type of single pulley is very often used as a machine even though it does not give any gain in mechanical advantage. For what purpose is such a pulley used?
If the weight of the movable pulley is W, obtain the expression for MA, VR, and efficiency.
