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प्रश्न
Answer the following in short.
Explain the various functions that a machine can perform.
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उत्तर
Various functions that a machine can perform are :
- Changing the direction of applied force − Example: When a flag is hoisted with the help of a pulley.
- Changing the magnitude of applied force − Example: Bottle opener multiplies the applied force and much less effort is required to open the cap.
- Applying force at a convenient point − Example: hi a pair of scissors, the input force is applied at the handle of the scissors which cuts the paper at the other end of the blade.
- Changing the speed of an object − Example: While riding a bicycle, force is applied on pedals which multiplies the speed.
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संबंधित प्रश्न
Rohan exerts a pull of 150 kgf. What is the maximum load he can raise with this pulley system if its efficiency = 75%?
What is a gear system ?
What is the use of a fixed pulley?
What is a block and tackle system of pulleys?
Give reason for the following:
The efficiency of a pulley is always less than 100%
(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?
What is a pulley?
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.
A pulley is a machine made up of a ______.
