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प्रश्न
What is a pulley?
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उत्तर
A pulley is an example of a simple type of machine. It is either a wooden or a metallic disc which can rotate about a horizontal axis passing through its centre. It has a grooved rim along which a rope or chain can slide. It is generally mounted in a framework called a block.
संबंधित प्रश्न
The mechanical advantage of an actual pulley is less than one. Give a reason. What is the justification for using the pulley then?
What is a gear system ?
Define the following term in reference to a gear system of Driving gear ?
Give reason for the following:
The lower block of a block and tackle pulley system must be of negligible weight
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 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?
What is a block and tackle system of pulleys? What precautions would you observe while rounding the string so that the effort is applied in the downward direction?
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?
_______ is a machine made up of wheel and rope.
A pulley is a machine made up of a ______.
