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प्रश्न
The diagram below shows a pulley arrangement.
(i) In the diagram, mark the direction of the forces due to tension, acting on the pulley P.
(ii) What is the purpose of the pulley Q?
(iii) If the tension is T newton, deduce the relation between T and E.
(iv) Calculate the velocity ratio of the arrangement.
(v) Assuming that the efficiency of the system is 100%, what is the mechanical advantage?
(vi) Calculate the value of E
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उत्तर
(ii) The purpose of the pulley Q is to change the direction of application of effort to a convenient direction.
(iii) In the diagram, T = E
(iv) If the free end of the string moves, through the distance x, the load will rise by a distance x/2.
Threfore, V.R = distance moved y the effort arm / distance moved by the load = `"x"/("x"//2) = 2`
(v) In equilibrium,L = 2T and E = T
efficiency = M.A / V. R
or, 1 = `("M ""A")/2`
⇒ M.A = 2
(vi) M.A = `"L"/"E"`
⇒ E = `"L"/("M"."A") = 100/2` = 50 N
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संबंधित प्रश्न
The pulley system has drawn lifts a load of 150 N when an effort of 60 N is applied. Find its mechanical advantage.
What is the mechanical advantage of an ideal pulley?
What is a gear system ?
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.
There is no gain in mechanical advantage in the case of a single fixed pulley. Explain, why the pulley is then used?
Draw a diagram of a single fixed pulley and obtain expressions for its:
(i) Mechanical advantage,
(ii) Velocity ratio, and
(iii) Efficiency, in the ideal case.
In a single movable pulley system, a load of 125 kgf is lifted by an effort of 75 kgf. Find the percentage efficiency of system.
A man raises a load of 360 kgf using a block and tackle system of 3 pulleys. If the efficiency of the pulley system is 60%, what effort is applied by the man?
State one advantage of single movable pulley.
