The escape velocity for a body projected vertically upwards from the surface of the earth is $11.2{\rm{\;\;km}}{{\rm{s}}^{ - 1}}$. If the body is projected in a direction making an angle of ${45^0}$ with the vertical, the escape velocity will be

$11.2{\rm{\;\;km}}{{\rm{s}}^{ - 1}}$

$11.2 \times \sqrt 2 {\rm{\;km}}{{\rm{s}}^{ - 1}}$

$11.2 \times 2{\rm{\;km}}{{\rm{s}}^{ - 1}}$

$11.2/\sqrt 2 {\rm{\;km}}{{\rm{s}}^{ - 1}}$

Back to GRAVITATION

Your Progress

0 / 392 Answered

Correct

Incorrect

Accuracy

JEE • PHYSICS • GRAVITATION

Gravitation practice · Medium

Try a question, then open “View answer” to check it. Sign in to submit answers and save progress.

Practice format and chapter quiz

These sets use single-correct-answer MCQs. They do not cover every JEE Main or JEE Advanced question format and are not full-length mock papers.

Take a chapter quiz →

Showing 1-30 of 392 questions

1 Medium

1 of 392

Understanding +4 | -1

The escape velocity for a body projected vertically upwards from the surface of the earth is

11.2\mathrm{\;\;km}{\mathrm{s}^{ - 1}}

. If the body is projected in a direction making an angle of

{45^0}

with the vertical, the escape velocity will be

View answer and explanation

Correct option: A

11.2\mathrm{\;\;km}{\mathrm{s}^{ - 1}}

Option A is correct because escape velocity is independent of the angle of projection.

2 Medium

2 of 392

Understanding +4 | -1

The escape velocity of a body projected from the surface of earth is

v_e

. If the body is projected at an angle

\theta

to the horizontal surface of earth, then the escape velocity would be

View answer and explanation

Correct option: A

v_e

Option A (

v_e

) is correct because escape velocity is independent of the angle of projection; it only depends on the initial speed.

3 Medium

3 of 392

Application +4 | -1

If different planets have the same density but different radii, then the acceleration due to gravity on the surface of the planet is related to the radius (R) of the planet as

View answer and explanation

Correct option: B

\mathrm{g} \propto {R}

Option B (

\mathrm{g} \propto {R}

) is correct because the acceleration due to gravity is directly proportional to the radius when density is constant.

4 Medium

4 of 392

Understanding +4 | -1

Which of the following statement is absolutely correct about mass

View answer and explanation

Correct option: C

More the mass of a body, lesser will be its acceleration for a given force

Option C is correct because, according to Newton's Second Law (

F=ma

), for a given force, acceleration is inversely proportional to mass. Therefore, more mass means less acceleration.

5 Medium

5 of 392

Understanding +4 | -1

Statement I: An astronaut in a satellite feels weightlessness:

Statement II: As observed by another astronaut's in the same satellite, force of gravity and centrifugal force balance each other.

View answer and explanation

Correct option: B

If both Statement - I and Statement - II are true but Statement - II is not the correct explanation of Statement - I.

Option B is correct because both statements are true, but the balancing of gravity and centrifugal force is not the direct cause of weightlessness; it's the freefall condition.

6 Medium

6 of 392

Understanding +4 | -1

An iron ball and a wooden ball of the same radius are released from a height 'h' in vacuum. The time taken by both of them to reach the ground is

View answer and explanation

Correct option: B

Exactly equal

Option B (Exactly equal) is correct because in a vacuum, the only force acting on both balls is gravity, and acceleration due to gravity is independent of mass.

7 Medium

7 of 392

Application +4 | -1

A satellite of mass

1000 \mathrm{~kg}

is supposed to orbit the earth at a height of

2000 \mathrm{~km}

above the earth's surface. Find (a) its speed in the orbit, (b) its kinetic energy, (c) the potential energy of the earth-satellite system and (d) its time period. Mass of the earth

=6 \times 10^{24} \mathrm{~kg}

View answer and explanation

Correct option: A

6.9 \mathrm{~km/s};\,2.38 \times 10^{10} \mathrm{~J};-4.76 \times 10^{10} \mathrm{~J};\,2.1\text{ hour}

The correct answer is A (

6.9 \mathrm{~km/s};\,2.38 \times 10^{10} \mathrm{~J};-4.76 \times 10^{10} \mathrm{~J};\,2.1\text{ hour}

) because it correctly calculates the speed, kinetic energy, potential energy, and time period of the satellite.

8 Medium

8 of 392

Analyzing +4 | -1

A uniform circular ring of radius

R

is fixed in plane. A particle is placed on the axis of the ring at a distance much greater than

{R}

and allowed to fall towards the ring under the influence of the ring's gravity. The particle achieves a maximum speed

v

. The ring is replaced with one of the same (linear) mass density but radius

2 R

, and the experiment is repeated. What is the new maximum speed of the particle?

View answer and explanation

Correct option: C

v

Option C is correct because the potential energy difference is independent of the radius, leading to the same maximum speed.

9 Medium

9 of 392

Application +4 | -1

The ratio of the weights of a body on the earth’s surface, so that on the surface of a planet is 9 : 4. The mass of the planet is

\frac{1}{9}\mathrm{th}

of that of the earth. If

R

is the radius of the earth, what is the radius of the planet? (Take, the planets to have the same mass density)

View answer and explanation

Correct option: D

\frac{R}{2}

Option D (

\frac{R}{2}

) is correct because the radius of the planet is found to be half of the Earth's radius using the given ratio of weights and mass.

10 Medium

10 of 392

Understanding +4 | -1

A point mass

m

is placed at a distance

2 R

from the centre of the shell of mass

M

and radius

R

. The gravitational force exerted by shell on the point mass is

View answer and explanation

Correct option: B

\frac{G M m}{4 R^2}

Option B (

\frac{G M m}{4 R^2}

) is correct because the gravitational force exerted by a spherical shell on a point mass outside the shell is the same as if all the mass of the shell were concentrated at its center.

11 Medium

11 of 392

Understanding +4 | -1

For the planet-sun system identify the correct statement.

View answer and explanation

Correct option: B

The total energy of the system is conserved

Option B (The total energy of the system is conserved) is correct because in a planet-sun system, the total energy (kinetic + potential) remains constant due to the conservative nature of gravitational forces.

12 Medium

12 of 392

Understanding +4 | -1

A mass

m

is placed at a point B in the gravitational field of mass

M

. When the mass m is brought from

B

to near point A, its gravitational potential energy will

View answer and explanation

Correct option: C

Decrease

Option C is correct. Gravitational potential energy is negative and decreases as the distance between the masses decreases, becoming more negative.

13 Medium

13 of 392

Understanding +4 | -1

Considering rotational motion of earth. The acceleration due to gravity at the equator of earth is given by, (where

\omega=

angular velocity of earth,

\mathrm{R}=

radius of earth,

\mathrm{g}=

acceleration due to gravity)

View answer and explanation

Correct option: C

\mathrm{g}^{\prime}=\mathrm{g}-\omega^2 \mathrm{R}

Option C (

\mathrm{g}^{\prime}=\mathrm{g}-\omega^2 \mathrm{R}

) is correct because the effective acceleration due to gravity at the equator is reduced due to the centrifugal force caused by Earth's rotation.

14 Medium

14 of 392

Application +4 | -1

The maximum and minimum distances of a comet from the sun are

8 \times {10^{12}}m

and

1.6 \times {10^{12}}m

. If its velocity when nearest to the sun is

60\,\,m/s

. What will be its velocity in

m/s

, when it is farthest?

View answer and explanation

Correct option: A

Option A (12) is correct because it is derived from the conservation of angular momentum, where the product of velocity and distance remains constant.

15 Medium

15 of 392

Application +4 | -1

A body is projected upwards with a velocity of

3 \times 11.2 \mathrm{~km} \mathrm{~s}^{-1}

from the surface of earth. What will be the velocity of the body when it escapes from the gravitational pull of earth?

View answer and explanation

Correct option: D

\sqrt{8} \times 11.2 \mathrm{~kms}^{-1}

Option D (

\sqrt{8} \times 11.2 \mathrm{~kms}^{-1}

) is correct because it calculates the final velocity after escaping Earth's gravity using energy conservation.

Explore Other Chapters in PHYSICS

View All →

UNITS & MEASUREMENTS 633 MCQs WAVES 566 MCQs THERMAL PROPERTIES OF MATTER 564 MCQs WORK-ENERGY-POWER 553 MCQs MOTION IN PLANE 530 MCQs OSCILLATIONS 498 MCQs

16 Medium

16 of 392

Understanding +4 | -1

If the earth stops rotating in its orbit about the sun, the value of

g

changes at

View answer and explanation

Correct option: D

no where

Option D is correct because the value of g is primarily affected by the Earth's mass and radius and is not directly influenced by the Earth's rotation around the Sun.

17 Medium

17 of 392

Analyzing +4 | -1

Assertion: If the earth expands in size without any change in mass, the length of the day would increase.
Reason: The rotation of earth about its axis follows the law of conservation of angular momentum.

View answer and explanation

Correct option: A

Assertion is true, Reason is true; Reason is the correct explanation of Assertion

Option A is correct because if the Earth expands without mass change, its moment of inertia increases, leading to a decrease in angular velocity and thus an increase in the length of the day, due to conservation of angular momentum.

18 Medium

18 of 392

Analyzing +4 | -1

Assertion: It we double the circular radius of a satellite, then its potential energy, kinetic energy and total mechanical energy will become half.

Reason: Orbital speed of a satellite,

v \propto \frac{1}{\sqrt{r}}

where,

r

is its radius of orbit.

View answer and explanation

Correct option: B

If both Assertion and Reason are true but Reason is not the correct explanation of Assertion

Option B is correct because both the assertion and the reason are true, but the reason does not correctly explain the assertion. The energy changes are due to the inverse relationship with the radius, not solely the orbital speed.

19 Medium

19 of 392

Understanding +4 | -1

Which of the following statements is/are true?
For the particle on the surface of earth

View answer and explanation

Correct option: D

the angular speed is

7.3 \times 10^{-5} \mathrm{rad} / \mathrm{s}

at the equator

Option D (the angular speed is

7.3 \times 10^{-5} \mathrm{rad} / \mathrm{s}

at the equator) is correct because the angular speed of Earth's rotation is constant for all points on the surface and equals to approximately

7.3 \times 10^{-5} \mathrm{rad} / \mathrm{s}

20 Medium

20 of 392

Understanding +4 | -1

The time period of an earth satellite in circular orbit is independent of

View answer and explanation

Correct option: A

The mass of the satellite

Option A (The mass of the satellite) is correct because the time period of a satellite's orbit depends on the radius of the orbit and the mass of the central body (Earth), but not the satellite's mass.

21 Medium

21 of 392

Analyzing +4 | -1

Assertion: A particle is projected upwards with speed

v

and it goes to a height

h

. If we double the speed then it will move to height

4 h

.

Reason: In case of earth, acceleration due to gravity

g

varies as

g \propto \frac{1}{r^2}

(for

r \geq R

)

View answer and explanation

Correct option: D

If Assertion is false but the Reason is true

Option D is correct. The Assertion is false because the height reached is proportional to the square of the initial velocity only if 'g' is constant. The Reason is true because acceleration due to gravity varies inversely with the square of the distance from the Earth's center.

22 Medium

22 of 392

Application +4 | -1

At what altitude will the acceleration due to gravity be

25 \%

of that at the earth's surface (given radius of the earth is

\mathrm{R}

)

View answer and explanation

Correct option: B

\mathrm{R}

Option B (

\mathrm{R}

) is correct because it is derived from the inverse square law relationship between gravitational acceleration and distance from the Earth's center.

23 Medium

23 of 392

Application +4 | -1

The required kinetic energy of an object of mass m, so that it may escape, will be

View answer and explanation

Correct option: C

mgR

Option C (

mgR

) is correct because the kinetic energy required for an object to escape is equal to its gravitational potential energy at the surface of the planet.

24 Medium

24 of 392

Application +4 | -1

At what height in km over the earth’s pole the free fall acceleration decreases by one percent? (Assume the radius of the earth to be 6400 km)

View answer and explanation

Correct option: A

Option A (32) is correct because using the formula for the variation of g with height, the height at which the acceleration due to gravity decreases by 1% is approximately 32 km.

25 Medium

25 of 392

Application +4 | -1

The K.E of a satellite is

{10^4}J

. It s P.E is

View answer and explanation

Correct option: C

- 2 \times {10^4}\,J

Option C (

- 2 \times {10^4}\,J

) is correct because the potential energy of a satellite is -2 times its kinetic energy.

26 Medium

26 of 392

Understanding +4 | -1

Time period of pendulum, on a satellite orbiting the earth, is

View answer and explanation

Correct option: D

infinity

Option D (infinity) is correct because the effective gravitational acceleration inside an orbiting satellite is zero, leading to an infinite time period for a pendulum.

27 Medium

27 of 392

Analyzing +4 | -1

Which of the following quantities does not depend upon the orbital radius of a satellite? (Take,

R=

radius of orbit)

View answer and explanation

Correct option: D

\frac{T^2}{R^3}

Option D is correct because Kepler's Third Law states that the square of the period is proportional to the cube of the orbital radius, making

\frac{T^2}{R^3}

a constant.

28 Medium

28 of 392

Application +4 | -1

Two bodies of masses

100kg

and

10,000\,\,kg

are at a distance of

1m

apart. At what distance from

100kg

on the line joining them will the resultant gravitational field intensity be zero.

View answer and explanation

Correct option: C

\frac{1}{{11}}m

from

{m_1}

Option C (

\frac{1}{{11}}m

from

{m_1}

) is correct because at this point the gravitational field intensities due to both masses are equal and opposite, resulting in a net zero field.

29 Medium

29 of 392

Application +4 | -1

The height at which the acceleration due to gravity becomes

\frac{g}{9}

(Where

g

is the acceleration due to gravity on the surface of the earth) in terms of the radius of the earth R is

View answer and explanation

Correct option: D

h = 2R

Option D (

h = 2R

) is correct because it is derived from the formula relating acceleration due to gravity at a height h to the radius of the Earth R.

30 Medium

30 of 392

Application +4 | -1

A satellite with kinetic energy

{E_k}

is revolving round the earth in a circular orbit. How much more kinetic energy should be given to it so that it may just escape into outer space

View answer and explanation

Correct option: A

{E_k}

Option A (

{E_k}

) is correct because the additional kinetic energy required for escape is equal to the initial kinetic energy in a circular orbit.

Revision notes and key takeaways

Review GRAVITATION in your textbook or class notes, then use this set to check your understanding.

Key Takeaways

✓ This set contains 392 single-correct-answer MCQs on GRAVITATION.
✓ Try each question before opening its answer. Read the explanation where one is available.
✓ Sign in to save submitted answers. Revisit incorrect answers alongside your textbook or class notes.

Showing 1-30 of 392 questions

Continue Your Practice

📚 Switch Set (MEDIUM)

Chapter Sets

ALL 450 MCQs EASY 53 MCQs HARD 5 MCQs MEDIUM 392 MCQs

0 /392

0✓ 0✗

0% Accuracy