Page 1 - IX-PHY-CH- 9-GRAVITATION

SAI INTERNATIONAL SCHOOL

PHYSICS

COMPETENCY BASED QUESTIONS

CLASS -IX

Chapter: GRAVITATION

Objective Questions:
1. When a banana falls from a tree, then the which of the following is true?
a) the banana is only attracted to the Earth.
b) The banana is the only thing that draws the earth,
c) the banana and the earth are attracted to each other with same gravitational force.
d) The banana and earth oppose each other.
2. Hemant throws the ball up in the sky. What kind of force will accelerate the ball downwards?
a) Positive frictional force,
b) negative frictional force,
c) positive gravity,
d) negative gravity.
3. A boy is whirling a stone, tied with a thread in the horizontal, circular path. If the stone is
broken from the string,
a) It will proceed in a straight line towards a circular path.
b) Center will move in a straight line tangential to circular path.
c) Will move away from the boy in a straight line perpendicular to circular path.
d) Will keep moving in a circular pattern.
4. What would happen if the Earth’s mass is increased, but its radius stayed the same.
a) The acceleration due to gravity would decrease.
b) The acceleration due to gravity would increase.
c) The acceleration due to gravity would stay the same.
d) The acceleration due to gravity would become zero.
5. The weight of an object at the centre of the earth of radius R is
a) zero
b) infinite
c) R times the weight at the surface of the earth
2
d) 1/ times the weight at surface of the earth
DIRECTIONS for the question 1 to 20: In each of the questions given below, there are
two statements marked as Assertion (A) and Reason (R). Mark your answer as per the
codes provided below:
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. A is false but R is true.
5. Both A and R are false.
7.Assertion: When distance between two bodies is doubled and mass of each body is
doubled, then the gravitational force between them remains the same.
Reason: According to Newton’s law of gravitation, force is directly proportional to the
product mass of bodies and inversely proportional to square of the distance between them.

8. Assertion: The acceleration of a freely falling heavier body will be greater than the
lighter body. The fall acceleration of heavier bodies is greater.