STD-IX, CBSE BOARD, NCERT BOOK, GRAVITATION, MCQs ON ACCELERATION DUE TO GRAVITY (g)

1.  When a body is thrown up, the force of gravity is-

(a) in the upward direction

(b) in the downward direction

(c) zero

(d) in the horizontal direction

 

ANS: in the downward direction

 

2.  When an object is thrown up, the force of gravity-

(a) is opposite to direction of motion

(b) is in the same direction of motion

(c) becomes zero at the highest point

(d) increases as it rises up

 

ANS: is opposite to the direction of motion

 

3.  In vacuum, all freely falling objects-

(a) have the same speed

(b) have the same velocity

(c) have the same force

(d) have the same acceleration

 

ANS: have the same acceleration

 

4.  Choose the correct statement.

(a) all bodies repel each other in the universe

(b) our earth does not behave like a magnet

(c) acceleration due to gravity is 8.9 ms^-2

(d) all bodies fall at the same rate in vacuum

 

ANS: all bodies fall at the same rate in vacuum

 

5.  A heavy stone falls (if air resistance is neglected)-

(a) faster than a light stone

(b) slower than a light stone

(c) with same acceleration as a light ball falls

(d) none of these

 

ANS: with same acceleration as a light ball falls

 

6.  Two bodies A and B of mass 500 g and 200 g respectively are dropped near the earth’s surface. Let the acceleration of A and B be a_A and a_B respectively, then-

(a) a_A = a_B

(b) a_A > a_B

(c) a_A < a_B

(d) can’t say

 

ANS: a_A = a_B

 

7.  Two iron and wooden balls identical in size are released from the same height in vacuum. The time taken by them to reach the ground are-

(a) not equal

(b) exactly equal

(c) may or may not be equal

(d) zero

 

ANS: exactly equal

 

8.  A sheet of paper and another sheet of paper crumpled into a ball are dropped from the top of a tower-

(a) sheet of paper reach the ground earlier than the ball

(b) sheet of paper reach the ground later than the ball

(c) both sheet of paper and ball reach the ground simultaneously

(d) sheet of paper remains in the air

 

ANS: sheet of paper reach the ground later than the ball

 

9.  The acceleration due to gravity near the moon’s surface is-

(a) approximately equal to that near the earth’s surface

(b) approximately six time that near the earth’s surface

(c) approximately one-sixth of that near the earth’s surface

(d) slightly greater than that near the earth’s surface

 

ANS: approximately one-sixth of that near the earth’s surface

 

10.  The acceleration due to gravity is g_e on Earth and g_m on Moon-

(a) g_e = g_m

(b) g_e < g_m

(c) g_e = g_m/6

(d) g_m = g_e/6

 

ANS: g_m = g_e/6

 

STD-IX, NCERT, CBSE BOARD, GRAVITATION, MCQs

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

 

ANS: will move along a straight line tangential to the circular path (it is 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

 

ANS: move out tangentially

 

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

 

ANS: move tangentially and escape away

 

4.  The universal law of gravitation was proposed by

(a) Copernicus

(b) Newton

(c) Galileo

(d) Archimedes

 

ANS: 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

 

ANS: 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

 

ANS: 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

 

ANS: 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

 

ANS: any two bodies having some mass

 

9.  The type of force which exists between charged bodies is-

(a) only gravitational

(b) neither gravitational

(c) only electrical

(d) both electrical and gravitational

 

ANS: both electrical and gravitational

 

10.  The gravitational force is-

(a) the weakest force

(b) the strongest force

(c) a short-range force

(d) non-central force

 

ANS: the weakest force

 

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

QUIZ ON LAW OF GRAVITATION

Quiz

 

1. 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
2. Inverse square law means,
   1.   (a) ∝ r
   2.   (b) ∝ r-1
   3.   (c) ∝ r-2
   4.   (d) ∝ r2
3. 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
4. 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)
5. 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
6. 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
7. 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
8. 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
9. 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
10. 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.