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प्रश्न
Which class of lever found in the human body is being used by a boy when he raises the weight of his body on his toes?
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उत्तर
Class II lever.
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संबंधित प्रश्न
A 4 m long rod of negligible weight is to be balanced about a point 125 cm from one end and a load of 18 kgf is suspended at a point 60 cm from the support on the shorter arm.
- If a weight W is placed at a distance of 250 cm from the support on the longer arm to balance the rod, find W.
- If a weight 5 kgf is kept to balance the rod, find its position.
- To which class of lever does it belong?
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?
The Physical balance
The following belong to which class of lever?
Fore-arm
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.
When we want to use a machine as a force multiplier, which class of lever should we preferably use? Give a simple diagram of such a lever.

The diagram shows the use of a lever.

- State the principle of moments as applied to the above lever.
- Which class of lever is this? Give an example of this class of lever.
- If FA = 100 cm, AB = 90 cm, calculate the minimum effort required to lift the load.
