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प्रश्न
State the principle of a lever?
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उत्तर
A lever works on the principle of moments. For an ideal lever, it is assumed that the lever is weightless and frictionless. In the equilibrium position of the lever, by the principle of moments,
Moment of load about the fulcrum = Moment of effort about the fulcrum.
Load × Load arm = Effort × Effort arm
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संबंधित प्रश्न
Class II levers are designed to have ______.
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.
Give three examples for leavers of 1st order.
The following belong to which class of lever?
Human-arm
The following belong to which class of lever?
Pliers Tools
The following belong to which class of lever?
A pair of scissors
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?
The following are an example of levers. State the class of lever to which each one belongs giving the relative positions of Load (L), Effort (E), Fulcrum (F):
(i) Scissors (ii) Sugar tongs (iii) Nutcracker (iv) Pliers.
Draw a labelled sketch of a second class lever. Give one example of such a lever.
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.
