Home
School Exams
Scholarship Exams
OTI365 - NTSE - X Standard
NTSE SAT Physics - Gravitation Sample Questions with Answer

NTSE SAT Physics - Gravitation

Exam Duration: 45 Mins Total Questions : 30

1 )

Name the fundamental force which holds the planets in their orbits around the sun.

(a)
Gravitational force of attraction
(b)
Electrostatic force of attraction
(c)
Nuclear force of attraction
(d)
Electrostatic force of attraction

2 )

The weight of an object of mass 15 kg at the centre of the earth is ________

(a)
147N
(b)
147kg
(c)
Zero
(d)
150N

3 )

A satellite of the earth is revolving in a circular orbit with a uniform speed v. If the gravitational force suddenly disappears, the satellite will :

(a)
Continue to move with velocity v along the original orbit
(b)
Fall down with increasing velocity
(c)
Move with a velocity v tangentially to the original orbit
(d)
Ultimately come to rest somewhere on the original orbit

4 )

Units of Relative Density are

(a)
Kg/m³
(b)
Unit less
(c)
Depends on the density of the substance
(d)
Depend on the density of water

5 )

Mass per unit volume of a substance is called

(a)
Density
(b)
Relative density
(c)
Specific gravity
(d)
None

6 )

The period of geostationary artificial satellite is

(a)
24 hours
(b)
6 hours
(c)
12 hours
(d)
48 hours

7 )

A satellite is revolving around the sun in a circular orbit with uniform velocity v. If the gravitational force suddenly disappears, the velocity of the satellite will be

(a)
Zero
(b)
v
(c)
2v
(d)
Infinity

8 )

A satellite moving uniform in a circular orbit around the earth in matter face space

(a)
does not need supply of energy for its motion
(b)
derives energy from the sun from its motion
(c)
is supplied energy for the motion from the ground control station
(d)
is supplied energy from the motion by the gravitational field of the earth

9 )

If R is the radius of the earth and g is the acceleration due to gravity, the mass of the earth is given by

(a)
\(GR\over g\)
(b)
\(g{R\over G}\)
(c)
\(g^2R\over G\)
(d)
\(gR^2\over G\)

10 )

Two objects of different masses falling freely near the surface of moon would

(a)
have same velocities at any instant
(b)
have different accelerations
(c)
experience forces of same magnitude
(d)
undergo a change in their inertia

11 )

An object is put one by one in three liquids having different densities. The object floats with 1/9, 2/11 and 3/7 parts of their volumes outside the liquid surface in liquids of densities d₁, d₂ and d₃ respectively. Which of the following statement is correct?

(a)
d₁> d₂> d₃
(b)
d₁> d₂< d₃
(c)
d₁< d₂> d₃
(d)
d₁< d₂< d₃

12 )

The value of quantity G in the law of gravitation

(a)
depends on mass of earth only
(b)
depends on radius of earth only
(c)
depends on both mass and radius of earth
(d)
is independent of mass and radius of the earth

13 )

The atmosphere is held to the earth by

(a)
gravity
(b)
wind
(c)
clouds
(d)
earth's magnetic field

14 )

The force of attraction between two unit point masses separated by a unit distance is called

(a)
gravitational potential
(b)
acceleration due to gravity
(c)
gravitational field
(d)
universal gravitational constant

15 )

A body is weighed at the poles and then at the equator.The weight

(a)
at the equator will be greater than at the poles
(b)
at the poles will be greater than at the equator
(c)
at the poles will be equal to the weight at the equation
(d)
depends upon the object

16 )

SI unit of g is

(a)
m²/s
(b)
s/m²
(c)
m/s²
(d)
m/s

17 )

SI unit of G is

(a)
N² m²/kg
(b)
N m²/kg
(c)
N m/kg
(d)
N m²/kg²

18 )

The value of g near the earth's surface is

(a)
8.9 m/s²
(b)
8.9 m/s
(c)
9.8 m/s²
(d)
9.8 m/s

Solution :

A geostationary satellite

19 )

A geostationary satellite

(a)
moves faster than the near earth satellite
(b)
has a time period less that of a near earth satellite
(c)
revolves about the polar axis
(d)
is stationary is space

20 )

The force of gravitation exists

(a)
everywhere in the universe
(b)
at the surface of the earth only
(c)
inside the earth only
(d)
at the surface of the moon only

21 )

One g wt. is equal to

(a)
9.8N
(b)
980N
(c)
0.0098 N
(d)
0.98 N

22 )

A hypothetical planet has density radius R. and surface gravitational acceleration g. If the radius of the planet were doubled, but the planetary density stayed the same, the acceleration due to gravity at the planet's surface would be

(a)
4g
(b)
2g
(c)
g
(d)
g/2

23 )

If a satellite is revolving near the earth's surface then its orbital velocity depends upon

(a)
the mass of the satellite
(b)
the radius of the earth
(c)
the radius of the orbit
(d)
the mass of the earth

24 )

The acceleration due to gravity

(a)
has the same value everywhere in space
(b)
has the same value everywhere on the earth
(c)
varies with the latitude on the earth
(d)
is greater on the moon due to its smaller diameter

25 )

A satellite which is geostationary in a particular orbit is taken to another orbit. Its distance from the centre of earth in new orbit is 2 times than that of the earlier orbit. The time period in the second orbit is

(a)
4.8 hours
(b)
24 hours
(c)
48√2 hours
(d)
24√2 hours

26 )

A ball is dropped from a spacecraft revolving around the earth at height of 120 k,. What will happen to the ball?

(a)
It will continue to move with the same speed along the original orbit of spacecraf
(b)
It will move with the same speed, tangentially to the spacecraft
(c)
If will fall down to the eath gradually
(d)
It will go very far in space

27 )

consider a heavenly body whose mass is 3 10²⁴ kg (half of that of the earth) and radius is 3200 krn (half of that of the earth). The acceleration due to gravity at the surface of this heavenly body will be

(a)
39.6 m/s²
(b)
19.6 m/s²
(c)
29.6 m/s²
(d)
49.6 m/s²

28 )

Communications satellites move in the orbit of radius 44,400 km around the earth. The acceleration of such a satellite assuming that the only force acting on it is that due to the earth is