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प्रश्न
The diagram below shows a lever in use:
- To which class of levers does it belong?
- Without changing the dimensions of the lever, if the load is shifted towards the fulcrum what happens to the mechanical advantage of the lever?
उत्तर
- It belongs to the class-II lever.
- Load shifting in the direction of the fulcrum will improve the lever's mechanical advantage.
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संबंधित प्रश्न
Name a machine to obtain gain in speed ?
State the principle of a lever?
A man uses a crowbar of length 1.5 m to raise a load of 75 kgf by putting a sharp edge below the bar at a distance 1 m from his hand.
- Draw a diagram of the arrangement showing the fulcrum (F), load (L) and effort (E) with their directions.
- State the kind of lever.
- Calculate:
- load arm,
- effort arm,
- mechanical advantage and
- the effort needed.
A lever of length 9 cm has its load arm 5 cm long and the effort arm is 9 cm long.
- To which class does it belong?
- Draw a diagram of the lever showing the position of fulcrum F and directions of both the load L and effort E.
- What is the mechanical advantage and velocity ratio if the efficiency is 100%?
- What will be the mechanical advantage and velocity ratio if the efficiency becomes 50%?
Which type of levers have mechanical advantage always more than 1? Give reasons.
The following belong to which class of lever?
Human-arm
The following belong to which class of lever?
A fire tongs
The following belong to which class of lever?
Knife
Shears, used for cutting metals and scissors used for cutting clothes are both examples of levers of the first order. However, whereas the shears always have short blades and long handles, the scissors often have blades much longer than the handles. Explain, why this is so?
A crowbar of length 100 cm is used to lift a load of 5 kgf. It has its fulcrum at a distance of 20 cm from the load. Calculate:
(i) the mechanical advantage of a crowbar and,
(ii) the effort applied at the other end.
