Class 9 - Practice - Level 1 - Gravitation

Total questions: 40

Who formulated the Universal Law of Gravitation?

Topic: Universal Law of Gravitation

Albert Einstein

Isaac Newton

Galileo Galilei

Johannes Kepler

None

The gravitational force between two objects depends on which of the following factors?

Topic: Gravitational Force

Their masses

The distance between them

Both A and B

Neither A nor B

None

What is the value of the gravitational constant G?

Topic: Gravitational Constant

$ \displaystyle 6.67\times {{10}^{{-11}}}\,N{{m}^{2}}/k{{g}^{2}}$

$ \displaystyle 9.8\,m/{{s}^{2}}$

$ \displaystyle 3.14$

$ \displaystyle 1.6\times {{10}^{{-19}}}\,C$

None

What is the relation between weight and mass?

Topic: Weight and Mass

Weight is mass times the acceleration due to gravity

Weight is mass divided by the acceleration due to gravity

Weight is independent of mass

Weight is mass times velocity

None

When an object is in free fall, the only force acting on it is:

Topic: Free Fall

Air resistance

Tension

Gravitational force

Friction

None

What is the approximate value of acceleration due to gravity on the surface of the Earth?

Topic: Acceleration due to Gravity

$ \displaystyle {9.8\,m/{{s}^{2}}}$

$ \displaystyle {6.67\times {{{10}}^{{-11}}}\,m/{{s}^{2}}}$

$ \displaystyle {1.6\times {{{10}}^{{-19}}}\,m/{{s}^{2}}}$

$ \displaystyle {3.14\,m/{{s}^{2}}}$

None

If the mass of an object is 10 kg, what is its weight on the surface of the Earth?

Topic: Mass and Weight

10 N

9.8 N

100 N

98 N

None

Why do all objects fall at the same rate in a vacuum?

Topic: Earth's Gravity

Because there is no gravity in a vacuum

Because there is no air resistance in a vacuum

Because objects have no mass in a vacuum

Because objects are weightless in a vacuum

None

What is the gravitational potential energy of an object of mass 5 kg placed at a height of 10 meters above the ground? $ \displaystyle \left( {Use\text{ }g\text{ }=\text{ }9.8\,m/{{s}^{2}}} \right)$

Topic: Gravitational Potential Energy

490 J

50 J

98 J

4900 J

None

10.

The point where the total mass of a body can be considered to be concentrated is called:

Topic: Centre of Mass

Centre of gravity

Centre of mass

Centre of buoyancy

Centre of pressure

None

11.

If the distance between two objects is doubled, the gravitational force between them becomes

Topic: Gravitational Attraction

Four times

Half

Double

One-fourth

None

12.

Astronauts feel weightless in a spacecraft orbiting the Earth because:

Topic: Weightlessness

There is no gravity in space

The spacecraft is in free fall

The gravitational force is very strong

They are far from the Earth

None

13.

An object will float in a fluid if its density is:

Topic: Buoyancy

Greater than the density of the fluid

Less than the density of the fluid

Equal to the density of the fluid

Independent of the density of the fluid

None

14.

According to Archimedes' Principle, the buoyant force on an object submerged in a fluid is equal to:

Topic: Archimedes' Principle

The weight of the fluid displaced by the object

The weight of the object

The volume of the object

The density of the fluid

None

15.

If a piece of wood has a mass of 50 grams and a volume of 100 cubic centimeters, what is its density?

Topic: Density

$ \displaystyle {0.5\text{ }g/cm{}^\text{3}}$

$ \displaystyle {1\text{ }g/cm{}^\text{3}}$

$ \displaystyle {2\text{ }g/cm{}^\text{3}}$

$\displaystyle {5\text{ }g/cm{}^\text{3}}$

None

16.

The acceleration due to gravity on the Moon is approximately:

Topic: Gravity on the Moon

$ \displaystyle {1.6\,m/{{s}^{2}}}$

$ \displaystyle {9.8\,m/{{s}^{2}}}$

$\displaystyle {3.7\,m/{{s}^{2}}}$

$ \displaystyle 24.8\,m/{{s}^{2}}$

None

17.

A region in which a mass experiences a force due to gravitational attraction is called:

Topic: Gravitational Field

Magnetic field

Electric field

Gravitational field

Electromagnetic field

None

18.

The weight of an object is:

Topic: Weight Variation

The same everywhere

More at the poles than at the equator

Less at the poles than at the equator

Independent of location

None

19.

The force with which the Earth attracts a body towards its center is called:

Topic: Gravitational Force on the Earth

Frictional force

Centripetal force

Gravitational force

Electromagnetic force

None

20.

Why do astronauts appear to float in space?

Topic: Weightlessness in Space

Because there is no gravity in space

Because they are in a state of free fall

Because they are weightless

Because the spacecraft moves at a constant velocity

None

21.

The point where the gravitational force can be considered to act on an object is called:

Topic: Centre of Gravity

Centre of mass

Centre of gravity

Centre of buoyancy

Centre of pressure

None

22.

Why does a feather fall slower than a stone in air?

Topic: Free Fall and Air Resistance

Because the feather has more mass

Because the feather has more air resistance

Because the stone is heavier

Because the stone is denser

None

23.

The value of g decreases with:

Topic: Variation of g

Increasing altitude

Increasing depth

Decreasing latitude

Increasing latitude

None

24.

Artificial satellites orbit the Earth due to:

Topic: Satellites

Centripetal force

Centrifugal force

Gravitational force

Electromagnetic force

None

25.

The condition in which objects appear to be weightless and float freely in a spacecraft is known as:

Topic: Microgravity

Hypergravity

Microgravity

Zero gravity

Reduced gravity

None

26.

Which of the following equations represents the gravitational force between two masses $ \displaystyle {{m}_{1}}\text{ }and\text{ }{{m}_{2}}$ separated by a distance r?

Topic: Gravitational Force Formula

$ \displaystyle F=G\frac{{{{m}_{1}}{{m}_{2}}}}{{{{r}^{2}}}}$

$ \displaystyle F\text{ }=G{{m}_{1}}{{m}_{2}}{{r}^{2}}$

$ \displaystyle F=G\frac{{{{m}_{1}}{{m}_{2}}}}{r}$

$ \displaystyle F=G\frac{{{{m}_{1}}{{m}_{2}}}}{{G{{r}^{2}}}}$

None

27.

The Law of Universal Gravitation helps to explain which of the following phenomena?

Topic: Law of Universal Gravitation

The motion of planets around the Sun

The tides in the ocean

The fall of an apple from a tree

All of the above

None

28.

Which formula is used to calculate the gravitational potential energy of an object of mass mmm at a height h above the ground?

Topic: Gravitational Potential Energy Formula

$ \displaystyle {U\text{ }=\frac{1}{2}\text{ }mgh}$

$ \displaystyle {U\text{ }=\text{ }mgh}$

$\displaystyle {U\text{ }=\text{ }\frac{{mgh}}{2}\text{ }}$

$ \displaystyle {U\text{ }=\text{ }\frac{{mg}}{h}\text{ }}$

None

29.

The inverse square law of gravitation states that the gravitational force between two objects is inversely proportional to the:

Topic: Inverse Square Law

Square of the distance between them

Square of the sum of their masses

Distance between them

Product of their masses

None

30.

The speed at which a satellite must travel to stay in orbit around the Earth is called:

Topic: Orbital Speed

Escape velocity

Terminal velocity

Orbital speed

Gravitational speed

None

31.

The acceleration due to gravity is maximum at:

Topic: Earth's Gravity Variation

The equator

The poles

The center of the Earth

The surface of the Earth

None

32.

The minimum velocity required to escape Earth's gravitational field is known as:

Topic: Escape Velocity

Terminal velocity

Escape velocity

Orbital velocity

Gravitational velocity

None

33.

According to Newton's Law of Gravitation, if the mass of one object is doubled, the gravitational force between two objects will:

Topic: Newton's Law of Gravitation

Remain the same

Double

Halve

Quadruple

None

34.

If a person weighs 60 kg on Earth, what would be their weight on the Moon?

Topic: Gravitational Force on Different Planets

50 N

20 N

60 N

10 N

None

35.

What are the units of the gravitational constant G?

Topic: Gravitational Constant Units

$\displaystyle {N{{m}^{2}}/k{{g}^{2}}}$

$ \displaystyle {m/{{s}^{2}}}$

$\displaystyle {kg/m}$

$ \displaystyle {m/N}$

None

36.

If the distance between two masses is tripled, the gravitational force between them becomes

Topic: Gravitational Force and Distance

One-ninth

One-third

Nine times

Three times

None

37.

Objects in a freely falling lift are:

Topic: Gravity and Weightlessness

Weightless

Heavier

Lighter

Unaffected

None

38.

Which of the following is not one of Kepler's laws of planetary motion?

Topic: Kepler's Laws

Law of Orbits

Law of Areas

Law of Periods

Law of Universal Gravitation

None

39.

Planets orbit the Sun in which shape according to Kepler’s first law?

Topic: Gravity and Orbits

Circular

Elliptical

Parabolic

Hyperbolic

None

40.

Which of the following changes will increase the gravitational force between two objects?

Topic: Factors Affecting Gravitational Force

Increasing the distance between them

Decreasing the distance between them

Decreasing the masses of both objects

Keeping the distance and masses constant

None

1 out of 40

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Class 9 - Practice - Level 1 - Gravitation

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