Advertisements
Advertisements
प्रश्न
Answer the following in short.
Explain the various functions that a machine can perform.
Advertisements
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.
APPEARS IN
संबंधित प्रश्न
A pulley system has three pulleys. A load of 120 N is overcome by applying an effort of 50N. Calculate the Mechanical Advantage and Efficiency of this system.
State if the following statement is true or false. Correct the statement if it is false.
A single movable pulley is a pulley that has its axis of rotation fixed.
Define the following term in reference to a gear system of Driving gear ?
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.
Name a machine which is used to:
change the direction of force applied.
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?
The alongside figure shows the combination of a movable pulley P1 with a fixed pulley P2 used for lifting up a load W.

(i) State the function of the fixed pulley P2.
(ii) If the free end of the string moves through a distance x, find the distance by which the load W is raised.
(iii) Calculate the force to be applied at C to just raise the load W = 20 kgf, neglecting the weight of the pulley P1 and friction.
A pulley system has a velocity ratio of 4 and an efficiency of 90%. Calculate:
(i) the mechanical advantage of the system.
(ii) the effort required to raise a load of 300 N by the system.
Complete the table.
| S. No | Types of Simple Machine | Example |
| 1. | Pulley | |
| 2. | Wheel and axle | |
| 3. | Wedge | |
| 4. | Inclined plan | |
| 5. | Lever | |
| 6. | Screw |
