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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?
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?
Define Lever
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?
Pliers Tools
The following belong to which class of lever?
A fire tongs
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.
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?
