Advertisements
Advertisements
प्रश्न
State two reasons, why the efficiency of a pulley system is not 100 percent?
Advertisements
उत्तर
The two reasons are:
(i) Some effort is used (or wasted) in overcoming the friction between the string and the grooves of the pulleys.
(ii) Some effort is used up (wasted) in lifting up the movable block along with the load.
On account of the above two reasons, effort applied is always more than the load lifted up and so the M.A. is always less than 1. Hence efficiency is always less than 100%.
संबंधित प्रश्न
State whether the following statement is True or False.
A pulley changes the direction of force.
What is the justification for using the pulley then ?
Answer the following in short.
Explain the various functions that a machine can perform.
Answer the following in detail.
How does a pulley make work simpler?
Define the following term in reference to a gear system of Driving gear ?
Define the following term in reference to a gear system for Gain in torque ?
In which direction does the force need to applied, when a single pulley is used with a mechanical advantage greater than one? How can you change the direction of force applied without altering its mechanical advantage? Draw a labelled diagram of the system.
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.
In the alongside the figure of two pulleys shown a system in which one pulley is fixed and the other is movable. What is the velocity ratio of the system?
An effort of 600 N is needed to lift a weight of 1000 N. What are the mechanical advantage and efficiency of the pulley system?
Draw the diagram of a single movable pulley and obtain its mechanical advantage, velocity ratio, and efficiency.
