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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
संबंधित प्रश्न
What is 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.
Which type of levers have mechanical advantage always more than 1? Give reasons.
The following belong to which class of lever?
The Physical balance
The following belong to which class of lever?
Human-arm
The following belong to which class of lever?
A claw-hammer
The following belong to which class of lever?
A pair of scissors
The following belong to which class of lever?
Nutcracker
The diagram below shows a lever in use.
(i) To which class of lever does it belong?
(ii) If FA = 40 cm, AB = 60 cm, then find the mechanical advantage of the lever.
The length of a nut-cracker is 12 cm. A nut, when kept at a distance of 4 cm from its fulcrum, requires an effort of 100 gf to crack it. What force will be required to crack the nut without using the nut-cracker?
