LEARNING SCIENCE

STD-IX, QUIZ ON BASICS OF GRAVITATION, MCQs, CBSE

QUIZ ON LAW OF GRAVITATION

Quiz

The universal law of gravitation is the force law also known as the-
1. (a) triangular law
2. (b) square law
3. (c) inverse square law
4. (d) parallelogram law
Inverse square law means,
1. (a) ∝ r
2. (b) ∝ r-1
3. (c) ∝ r-2
4. (d) ∝ r2
The force of gravitation between two bodies does not depend on-
1. (a) their separation
2. (b) product of their masses
3. (c) sum of their masses
4. (d) gravitational constant
Force of attraction between two bodies does not depend upon-
1. (a) the shape of bodies
2. (b) the distance between their centres
3. (c) the magnitude of their masses
4. (d) both (b) and (c)
In the relation F=G ( Mm)/d^2 , the quantity G
1. (a) depends on the value of g at a place
2. (b) is used only when earth is one of the two masses
3. (c) is universal constant in nature
4. (d) is greatest at the surface of the earth
Force of attraction between two objects each of mass 1 kg and separated by 1 m is called-
1. (a) gravitational potential
2. (b) acceleration due to gravity
3. (c) gravitational field
4. (d) universal gravitational constant
The value of G depends on-
1. (a) masses of the bodies
2. (b) distance between the bodies
3. (c) both (a) and (b)
4. (d) None
Which of the following statements regarding gravitational force existing between two bodies is TRUE?
1. (a) first body exerts attractive force on second body while second body exerts repulsive force on first body
2. (b) the gravitational force is zero when they are kept in vacuum
3. (c) force exerted by the first body on second is not equal to the force exerted by second body on first
4. (d) force exerted by first body on second body is equal to the force exerted by second body on first
When an apple falls from a tree -
1. (a) only earth attracts the apple
2. (b) only apple attracts the earth
3. (c) both the earth and the apple attract each other
4. (d) none attracts each other
Two particles of mass m1 and m2, approach each other due to their mutual gravitational attraction only. Then-
1. (a) accelerations of both the particles are equal
2. (b) acceleration of the particle of mass m1 is proportional to m1
3. (c) acceleration of the particle of mass m1 is proportional to m2
4. (d) acceleration of the particle of mass m1 is inversely proportional to m1

STD-IX, MCQs on GRAVITATION, CBSE BOARD

1. A boy is whirling a stone tied with a string in a horizontal circular path. The string breaks, the stone-

A) will continue to move in the circular path
B) will move along a straight line towards the centre of the circular path
C) will move along a straight line tangential to the circular path
D) will move along a straight line perpendicular to the circular path away from the boy

... Answer is C)
Due to inertia of motion.

2. Neglecting rotation of the earth, if suddenly the attractive power of the earth drops to zero, a man standing on the earth will

A) fly up
B) slide along the surface
C) move out tangentially
D) stand unaffected

... Answer is C)
due to inertia of motion.

3. If suddenly the gravitational force of attraction between earth and a satellite revolving around it becomes zero, then the satellite will-

A) continue to move in its orbit with same velocity
B) move tangentially and escape away
C) become stationary in its orbit
D) move towards the Earth

... Answer is B)
due to inertia of motion.

4. The universal law of gravitation was proposed by,

A) Copernicus
B) Newton
C) Archimedes
D) Kepler

... Answer is B)
Newton.

5. Newton’s law of gravitation is valid-

A) on the earth only
B) on the moon only
C) in the laboratory only
D) everywhere

... Answer is D)
everywhere.

6. Newton’s Law of gravitation:

A) can be verified in the laboratory
B) cannot be verified but is true
C) is valid only on Earth
D) is valid only in the solar system

... Answer is A)
It can be verified in the laboratory.

7. Law of gravitation is applicable for-

A) heavy bodies only
B) medium sized bodies only
C) small sized bodies only
D) bodies of any size

... Answer is D)
bodies of any size.

8. Law of gravitation gives the gravitational force between-

A) the earth and a point mass only
B) the earth and sun only
C) any two bodies having some mass
D) two charged bodies only

... Answer is C)
any two bodies having some mass.

9. The gravitational force is-

A) the weakest force
B) the strongest force
C) a short-range force
D) non-central force

... Answer is A)
It is the weakest force.

10. Gravitational force is a-

A) repulsive force
B) action at a distance force
C) neither a nor b
D) both a and b

... Answer is A)
neither a nor b.

MOST IMPORTANT MCQs ON KEPLER'S LAWS OF PLANETARY MOTION

Quiz

The orbits of planets around the sun are-
1. (a) circular
2. (b) parabolic
3. (c) elliptical
4. (d) straight
Which of the following statements are true?
(i) the orbit of a planet is elliptical with the sun at one of its foci
(ii) the line joining the planet and the sun sweeps equal areas in equal intervals of time
(iii) the square of the mean distance of a planet from the sun is proportional to the cube of its orbital period
1. (a) only (i) and (ii)
2. (b) only (ii) and (iii)
3. (c) only (i) and (iii)
4. (d) all are correct
According to Kepler’s law the relationship between T (time period of revolution of a planet) and r (the semi-major axis of the ellipse) is-
1. (a) T2 ∝ r
2. (b) T2 ∝ r2
3. (c) T2 ∝ r-3
4. (d) T ∝ r3/2
Which of the following graphs represent the motion of a planet about the sun?
1. (a)
2. (b)
3. (c)
4. (d)
The time period of a satellite is 5 hours. If the separation between the earth and the satellite is increased to 4 times, what will be the new time period?
1. (a) 20 hours
2. (b) 10 hours
3. (c) 80 hours
4. (d) 40 hours
The time period of revolution of planet A around the sun is 8 times that of B. How many times the distance of A from the sun is greater than that of B from the sun?
1. (a) 2
2. (b) 3
3. (c) 4
4. (d) 5
A planet moving around sun sweeps out area A1 in two days, A2 in three days and A3 in six days. Then the relation between A1, A2, and A3 is-
1. (a) 3A1 = 2A2 = A3
2. (b) 2A1 = 3A2 = 6A3
3. (c) 3A1 = 2A2 = 6A3
4. (d) 6A1 = 3A2 = 2A3