Question

Read the following statements carefully.

Statement 1: A lever is a simple machine which is used to lift heavy weights with the minimum amount of effort.
Statement 2: In the inclined plane, there is a slanting surface which connects two points at different heights so that the heavier objects can be moved up or down easily.
Statement 3: A Pulley is used to lift heavy objects by changing the direction of the force.
Statement 4: A screw is a simple machine made of wood or metal with at least one slanting side ending in a sharp or pointed edge.
Which of the following is an incorrect statement? State the reason for your answer.

• A. Statement 1
• B. Statement 2
• C. Statement 3
• D. Statement 4

Answer 1

The correct option is D

Statement 4

1. Statement 1: It is true because we can use a lever and fix one of its ends under the weight which is desired to be lifted and if we apply effort at the other and the weight can be easily lifted
2. Statement 2: It is true since an inclined slope helps to move a heavier object between two different positions which are situated at different heights.
3. Statement 3: It is true because using a pulley, the downward force that we exert could be converted to an upward force and an object can be lifted easily
4. Statement 4: The statement is wrong because wood can't be used to make screws as threads can't be carved out of wood.

Hence, option D is correct.