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प्रश्न
What is a lever?
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उत्तर
A lever is a special case of the application of the law of moments. It is a rigid bar, straight or bent, which is capable of rotation about a fixed point or a fixed-line, called the axis of rotation. This fixed point or the axis of rotation is called the fulcrum. An effort E is applied at point A of the lever to overcome resistance (or load) at another point B, as shown in the diagram.
संबंधित प्रश्न
Which class of lever will always have MA > 1 and why?
Draw a diagram of a lever which is always used as a force multiplier. How is the effort arm related to the load arm in such a lever?
shows a nut cracker name the class of lever ?
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.
Fig 3.17 below shows a lever in use.
(a) To which class of lever does it belong?
(b) If FA = 80 cm, AB = 20 cm, find its mechanical advantage.
(c) Calculate the value of E.
Which type of levers have mechanical advantage always more than 1? Give reasons.
The following belong to which class of lever?
Pliers Tools
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?
In the following diagram of a wheelbarrow, mark the fulcrum (F) and indicate the directions of load (L) and effort (E) with arrows.
What class of lever is it? Give one more example of the same class of lever.
