Advertisements
Advertisements
Question
What is a lever?
Advertisements
Solution
A lever is a simple machine consisting of a rigid rod that is capable of turning around a pivot called a fulcrum. It has three parts, namely effort, load, and fulcrum.
- Fulcrum: The rod of the lever rests on it and the lever rotates about it.
- Load: The weight lifted by the liver is called the load.
- Effort: The force applied on the other end of the rod to lift the load is called the effort.
APPEARS IN
RELATED QUESTIONS
Select the correct alternative:
For an ideal machine, the efficiency is
Can a machine have an efficiency of 100%? Give a reason to support your answer.
The diagram below shows a wheel barrow. Mark position of fulcrum F and draw arrows to show the directions of load L and effort E. What class of lever is the whell barrow? Give one more example of the same class of lever.

The correct relationship between the mechanical advantage (M.A.), the velocity ratio (V.R.) and the efficiency (n) is ______.
The mechanical advantage of an inclined place is always:
(a) less than 1
(b) equal to 1
(c) greater than 1
(d) nothing can be said
Give an example of the following uses of a machine:
to obtain gain in speed
Write an expression to show the relationship between mechanical advantage, velocity ratio, and efficiency for a simple machine.
A cook used a ‘fire tong pair’ of length 32 cm. to lift a piece of burning coal of mass 500 g. If he applies his effort at a distance of 8 cm from the fulcrum, what is his effort? Assume friction etc. to be absent. Also, obtain values of the M.A. and the V.R. of this ‘machine’.
Classify the following as a lever, a pulley and an inclined plane:
A knife
A pair of scissors is a _____ multiplier.
