Question

A) SELECT THE CORRECT OPTION FROM THE FOLLOWING :
1. Both A and R are true and R is the correct explanation of A . 2. Both A and R are true but R is not the correct explanation of A. 3. A is true, but R is false . 4. Both A and R are false 5. A is false ,R is true

Q1 . ASSERTION : No work is done when there is no motion or change in position.
REASON: Work is said to be done if the force applied on the body moves it.

Q2. ASSERTION: See- saw is an example for class II lever.
REASON: Class II lever has the load between the fulcrum and the effort.

Q3 .ASSERTION: Helium is a noble gas.
REASON: It is highly reactive element.

Q4.ASSERTION: Melting point of water is 100C.
REASON: Temperature at which liquids just boil and change over to vapor is called melting point.

Q5. ASSERTION: Brownian movement is minimum in solids.
REASON: Brownian movement is the random zig –zag movement of particles.

Q6 .ASSERTION : Liquids are highly diffusible.
REASON: In liquids ,the forces of attraction between the particles is less strong.

Q7. ASSERTION: Most of the nails cling near the ends of the magnet.
REASON: Attraction of magnet is minimum near its poles.

Q8. ASSERTION: North pole of one magnet attracts north pole of another magnet .
REASON: Like poles attract to each other.

Q9. ASSERTION: All the changes are reversible.
REASON: Changes are temporary.

Q10. ASSERTION: Conversion of milk into curd is physical change.
REASON: New substance is formed ,

Answer 1

The work is said to be done when there is a change in motion or there is displacement.

Explanation:

1. The assertion and reason both are true and it is the correct explanation.
2. The assertion is false but the reason is true. See-saw is an example of I class lever.
3. The assertion is true but the reason is false. Helium is a noble gas but it is a highly stable compound because of the fully complete outer shell. Thus, it highly unreactive.
4. Both assertion and reason are false. The melting point of water is 0°C. The temperature at which liquids just boil and change over to vapour is called the boiling point.
5. Both assertion and reason are true and it is a correct explanation.
6. Both the assertion and reason are true and it is a correct explanation.
7. The assertion is true but the reason is false. The attraction of magnet is maximum at the north pole.
8. Both assertion and reason are false. The north pole of the magnet attracts the south pole of another magnet. Like poles repel each other.
9. Both assertion and reason are false. Not all changes are reversible and only reversible change are temporary.
10. Both assertion and reason are true and the reason is the correct explanation.