Enhance your understanding of gravitation with over 1000 Gravitation MCQs and explanations, crafted specifically for Class 9 students to delve into gravitational forces, orbits, and celestial mechanics.

## 100+ Gravitation MCQs with Explanations for Class 9

Embark on a journey through Gravitation with our vast array of MCQs. Specifically curated for Class 9 students, this collection features over 100+ MCQs with explanations, offering a comprehensive understanding of gravitational forces, orbits, and celestial mechanics.

- A force of 20 N is applied on an object of mass 5 kg. What is the acceleration produced in the object?

A) 2 m/s²

B) 4 m/s²

C) 5 m/s²

D) 10 m/s²

Correct Option: B

Explanation: Using Newton’s second law, , where is the force applied, is the mass of the object, and is the acceleration produced. Rearranging the equation to find acceleration gives . - The gravitational force between two objects depends on:

A) Mass of both objects

B) Distance between the objects

C) Both mass and distance

D) None of the above

Correct Option: C

Explanation: According to Newton’s law of universal gravitation, the gravitational force between two objects depends on both their masses and the distance between them. - What is the SI unit of weight?

A) Newton

B) Kilogram

C) Joule

D) Pascal

Correct Option: A

Explanation: Weight is a force, and its SI unit is the Newton (N). - What is the value of acceleration due to gravity on the surface of the Earth?

A) 9.8 m/s²

B) 6.7 m/s²

C) 10 m/s²

D) 7.3 m/s²

Correct Option: A

Explanation: The acceleration due to gravity on the surface of the Earth is approximately . - The mass of the Earth is approximately:

A) kg

B) kg

C) kg

D) kg

Correct Option: A

Explanation: The mass of the Earth is approximately kg. - An object is dropped from a certain height. What is its velocity just before hitting the ground?

A) 0 m/s

B) 9.8 m/s

C) 19.6 m/s

D) Depends on the height

Correct Option: C

Explanation: Just before hitting the ground, the velocity of the object is the same as the final velocity of an object in free fall, which is approximately if the object is dropped from rest. - What happens to the gravitational force between two objects if the distance between them is doubled?

A) It becomes one-fourth

B) It becomes half

C) It remains the same

D) It becomes double

Correct Option: A

Explanation: According to Newton’s law of universal gravitation, the gravitational force is inversely proportional to the square of the distance between the objects. If the distance is doubled, the force becomes one-fourth. - Which of the following statements is true regarding artificial satellites?

A) They orbit around the Moon only

B) They are launched only for scientific purposes

C) They are used for communication, weather forecasting, etc.

D) They do not require any fuel to stay in orbit

Correct Option: C

Explanation: Artificial satellites are used for various purposes including communication, weather forecasting, navigation, and surveillance. - The weight of an object on the Moon is approximately what fraction of its weight on Earth?

A) One-fourth

B) One-half

C) Three-fourths

D) Equal

Correct Option: A

Explanation: The gravitational acceleration on the Moon is about one-sixth of that on Earth. Therefore, the weight of an object on the Moon is approximately one-sixth of its weight on Earth, which is one-fourth in terms of fraction. - Which of the following is a vector quantity?

A) Mass

B) Density

C) Force

D) Temperature

Correct Option: C

Explanation: Force is a vector quantity because it has both magnitude and direction. - An object is thrown vertically upwards. What happens to its acceleration as it goes higher?

A) Increases

B) Decreases

C) Remains constant

D) Becomes zero

Correct Option: B

Explanation: As the object goes higher, the acceleration due to gravity decreases, resulting in a decrease in its magnitude. - What is the value of acceleration due to gravity at a height where there is no atmosphere?

A) Zero

B) Same as on the surface of the Earth

C) Depends on the mass of the object

D) Depends on the radius of the Earth

Correct Option: B

Explanation: The acceleration due to gravity at a height where there is no atmosphere is the same as on the surface of the Earth, assuming no other significant gravitational influences. - Which of the following statements about the mass of an object is correct?

A) It varies with location

B) It depends on the gravitational field strength

C) It remains constant

D) It changes with temperature

Correct Option: C

Explanation: The mass of an object remains constant regardless of its location or the gravitational field strength acting upon it. - What happens to the weight of an object when it is taken to the Moon’s surface?

A) Increases

B) Decreases

C) Remains constant

D) Becomes zero

Correct Option: B

Explanation: The weight of an object decreases on the Moon’s surface because the gravitational acceleration on the Moon is less than that on Earth. - An object is moving with a constant velocity. What can be said about the net force acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: If an object is moving with a constant velocity, according to Newton’s first law of motion, the net force acting on it is zero. - Which of the following is an example of projectile motion?

A) A stone dropped from a cliff

B) A car moving on a straight road

C) A ball rolling down a hill

D) A rocket launching into space

Correct Option: A

Explanation: Projectile motion involves an object being launched into the air and moving under the influence of gravity alone. A stone dropped from a cliff follows a projectile motion trajectory. - What is the weight of an object of mass 10 kg?

A) 10 N

B) 9.8 N

C) 98 N

D) 100 N

Correct Option: C

Explanation: Weight is the force exerted on an object due to gravity. On the surface of the Earth, the acceleration due to gravity is approximately , so the weight of a object is . - What is the SI unit of force?

A) Newton

B) Joule

C) Watt

D) Kilogram

Correct Option: A

Explanation: The SI unit of force is the Newton (N). - An object is in free fall. What can be said about the net force acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In free fall, the only force acting on the object is the force due to gravity, which results in constant acceleration. Therefore, according to Newton’s second law, the net force is zero. - What is the direction of the gravitational force acting on an object in free fall?

A) Upwards

B) Downwards

C) Horizontal

D) Tangential to the surface

Correct Option: B

Explanation: The gravitational force acting on an object in free fall is always directed downwards, towards the center of the Earth. - What is the value of acceleration due to gravity at a height where there is no atmosphere?

A) Zero

B) Same as on the surface of the Earth

C) Depends on the mass of the object

D) Depends on the radius of the Earth

Correct Option: B

Explanation: The acceleration due to gravity at a height where there is no atmosphere is the same as on the surface of the Earth, assuming no other significant gravitational influences. - Which of the following statements about the mass of an object is correct?

A) It varies with location

B) It depends on the gravitational field strength

C) It remains constant

D) It changes with temperature

Correct Option: C

Explanation: The mass of an object remains constant regardless of its location or the gravitational field strength acting upon it. - What happens to the weight of an object when it is taken to the Moon’s surface?

A) Increases

B) Decreases

C) Remains constant

D) Becomes zero

Correct Option: B

Explanation: The weight of an object decreases on the Moon’s surface because the gravitational acceleration on the Moon is less than that on Earth. - An object is moving with a constant velocity. What can be said about the net force acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: If an object is moving with a constant velocity, according to Newton’s first law of motion, the net force acting on it is zero. - Which of the following is an example of projectile motion?

A) A stone dropped from a cliff

B) A car moving on a straight road

C) A ball rolling down a hill

D) A rocket launching into space

Correct Option: A

Explanation: Projectile motion involves an object being launched into the air and moving under the influence of gravity alone. A stone dropped from a cliff follows a projectile motion trajectory. - What is the weight of an object of mass 10 kg?

A) 10 N

B) 9.8 N

C) 98 N

D) 100 N

Correct Option: C

Explanation: Weight is the force exerted on an object due to gravity. On the surface of the Earth, the acceleration due to gravity is approximately , so the weight of a object is . - What is the SI unit of force?

A) Newton

B) Joule

C) Watt

D) Kilogram

Correct Option: A

Explanation: The SI unit of force is the Newton (N). - An object is in free fall. What can be said about the net force acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In free fall, the only force acting on the object is the force due to gravity, which results in constant acceleration. Therefore, according to Newton’s second law, the net force is zero. - What is the direction of the gravitational force acting on an object in free fall?

A) Upwards

B) Downwards

C) Horizontal

D) Tangential to the surface

Correct Option: B

Explanation: The gravitational force acting on an object in free fall is always directed downwards, towards the center of the Earth. - Which of the following is not a vector quantity?

A) Velocity

B) Force

C) Mass

D) Acceleration

Correct Option: C

Explanation: Mass is a scalar quantity as it only has magnitude and no direction. - If the mass of an object is halved while its weight remains constant, what happens to its acceleration due to gravity?

A) It is halved

B) It doubles

C) It remains the same

D) It becomes zero

Correct Option: B

Explanation: The weight of an object is directly proportional to its mass and the acceleration due to gravity. If the mass is halved and the weight remains constant, it means the acceleration due to gravity has doubled. - Which of the following is not an example of a contact force?

A) Friction

B) Tension

C) Magnetic force

D) Gravitational force

Correct Option: D

Explanation: Contact forces require physical contact between objects, while gravitational force acts at a distance without direct contact. - An object is thrown horizontally with a certain velocity. What can be said about its vertical velocity component?

A) It is zero

B) It is non-zero

C) It increases with time

D) It decreases with time

Correct Option: A

Explanation: When an object is thrown horizontally, its initial vertical velocity component is zero if there is no vertical force acting on it. - The weight of an object on the Moon is approximately what fraction of its weight on Earth?

A) One-sixth

B) One-fourth

C) One-half

D) Equal

Correct Option: A

Explanation: The gravitational acceleration on the Moon is about one-sixth of that on Earth. Therefore, the weight of an object on the Moon is approximately one-sixth of its weight on Earth. - Which of the following statements about gravitational force is incorrect?

A) It is always attractive

B) It depends on the masses of the objects

C) It decreases with distance

D) It acts along the line joining the centers of mass of the objects

Correct Option: C

Explanation: Gravitational force decreases with distance according to the inverse square law, not just decreases with distance. - An object is thrown vertically upwards. At the highest point, its velocity is:

A) Zero

B) Same as the initial velocity

C) Double the initial velocity

D) Cannot be determined

Correct Option: A

Explanation: At the highest point, the object momentarily comes to rest before falling back down. Therefore, its velocity at that point is zero. - Which of the following statements is true regarding the acceleration due to gravity?

A) It is greater at higher altitudes

B) It is greater at lower altitudes

C) It is independent of altitude

D) It varies with the density of the medium

Correct Option: C

Explanation: The acceleration due to gravity is approximately constant at a given location and is independent of altitude. - An object is thrown horizontally with a certain velocity from a certain height. How long does it take for the object to reach the ground?

A) Depends on the horizontal velocity

B) Depends on the height

C) Same as the time taken for vertical free fall from the same height

D) Cannot be determined

Correct Option: C

Explanation: The time taken for the object to reach the ground is the same as the time taken for vertical free fall from the same height, as horizontal motion does not affect the time of descent. - An object is in equilibrium. What can be said about the net force acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In equilibrium, the net force acting on an object is zero according to Newton’s first law of motion. - Which of the following statements about satellites in orbit around the Earth is true?

A) They are stationary relative to the Earth

B) They are not affected by gravity

C) They are constantly falling towards the Earth

D) They have no velocity

Correct Option: C

Explanation: Satellites in orbit around the Earth are constantly falling towards the Earth due to gravity, but their horizontal velocity allows them to remain in orbit without crashing into the Earth’s surface. - Which of the following is a correct unit for mass?

A) Newton

B) Kilogram

C) Meter per second squared

D) Joule

Correct Option: B

Explanation: Mass is measured in kilograms (kg). - What is the weight of an object on the surface of the Moon?

A) Less than its weight on Earth

B) Equal to its weight on Earth

C) Greater than its weight on Earth

D) Zero

Correct Option: A

Explanation: The gravitational acceleration on the Moon is less than that on Earth, so the weight of an object on the surface of the Moon is less than its weight on Earth. - Which of the following quantities is a measure of inertia?

A) Mass

B) Weight

C) Force

D) Acceleration

Correct Option: A

Explanation: Inertia is the resistance of an object to changes in its state of motion, and mass is a measure of this inertia. - An object is in free fall. What can be said about its acceleration?

A) It is zero

B) It is constant

C) It is increasing

D) It is decreasing

Correct Option: B

Explanation: In free fall, the only force acting on the object is gravity, resulting in a constant acceleration of approximately . - Which of the following statements about weight and mass is correct?

A) Weight is a scalar quantity, while mass is a vector quantity

B) Weight is measured in kilograms, while mass is measured in newtons

C) Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object

D) Weight and mass are the same physical quantity

Correct Option: C

Explanation: Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object. Weight is measured in newtons, while mass is measured in kilograms. - An object is thrown vertically upwards. What can be said about its acceleration at the highest point?

A) It is zero

B) It is constant

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: At the highest point, the object momentarily comes to rest before falling back down. Therefore, its acceleration at that point is zero. - Which of the following statements about projectile motion is true?

A) The horizontal component of velocity changes with time

B) The vertical component of velocity remains constant

C) The acceleration is zero throughout the motion

D) The motion is always in a straight line

Correct Option: B

Explanation: In projectile motion, the horizontal component of velocity remains constant, while the vertical component changes due to the influence of gravity. - What is the SI unit of weight?

A) Newton

B) Kilogram

C) Joule

D) Pascal

Correct Option: A

Explanation: Weight is a force, and its SI unit is the Newton (N). - What is the weight of an object on the surface of the Earth?

A) Same as its mass

B) Zero

C) Depends on the object’s volume

D) Depends on the object’s density

Correct Option: A

Explanation: The weight of an object on the surface of the Earth depends on its mass and the acceleration due to gravity, but it is not directly related to volume or density. - Which of the following statements about forces is incorrect?

A) Forces can change the shape of an object

B) Forces can change the speed of an object

C) Forces can change the direction of motion of an object

D) Forces can change the mass of an object

Correct Option: D

Explanation: Forces can affect the motion and shape of an object, but they do not change the mass of the object. - An object is in equilibrium. What can be said about the sum of the forces acting on it? A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In equilibrium, the sum of the forces acting on an object is zero according to Newton’s first law of motion. - Which of the following is not a contact force?

A) Friction

B) Tension

C) Magnetic force

D) Gravitational force

Correct Option: D

Explanation: Contact forces require physical contact between objects, while gravitational force acts at a distance without direct contact. - An object is thrown horizontally with a certain velocity. What can be said about its vertical acceleration?

A) It is zero

B) It is non-zero

C) It increases with time

D) It decreases with time

Correct Option: A

Explanation: When an object is thrown horizontally, its initial vertical velocity component is zero if there is no vertical force acting on it. - The weight of an object on the Moon is approximately what fraction of its weight on Earth?

A) One-sixth

B) One-fourth

C) One-half

D) Equal

Correct Option: A

Explanation: The gravitational acceleration on the Moon is about one-sixth of that on Earth. Therefore, the weight of an object on the Moon is approximately one-sixth of its weight on Earth. - Which of the following statements about gravitational force is incorrect?

A) It is always attractive

B) It depends on the masses of the objects

C) It decreases with distance

D) It acts along the line joining the centers of mass of the objects

Correct Option: C

Explanation: Gravitational force decreases with distance according to the inverse square law, not just decreases with distance. - An object is thrown vertically upwards. At the highest point, its velocity is:

A) Zero

B) Same as the initial velocity

C) Double the initial velocity

D) Cannot be determined

Correct Option: A

Explanation: At the highest point, the object momentarily comes to rest before falling back down. Therefore, its velocity at that point is zero. - Which of the following statements is true regarding the acceleration due to gravity?

A) It is greater at higher altitudes

B) It is greater at lower altitudes

C) It is independent of altitude

D) It varies with the density of the medium

Correct Option: C

Explanation: The acceleration due to gravity is approximately constant at a given location and is independent of altitude. - An object is thrown horizontally with a certain velocity from a certain height. How long does it take for the object to reach the ground?

A) Depends on the horizontal velocity

B) Depends on the height

C) Same as the time taken for vertical free fall from the same height

D) Cannot be determined

Correct Option: C

Explanation: The time taken for the object to reach the ground is the same as the time taken for vertical free fall from the same height, as horizontal motion does not affect the time of descent. - An object is in equilibrium. What can be said about the net force acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In equilibrium, the net force acting on an object is zero according to Newton’s first law of motion. - Which of the following statements about satellites in orbit around the Earth is true?

A) They are stationary relative to the Earth

B) They are not affected by gravity

C) They are constantly falling towards the Earth

D) They have no velocity

Correct Option: C

Explanation: Satellites in orbit around the Earth are constantly falling towards the Earth due to gravity, but their horizontal velocity allows them to remain in orbit without crashing into the Earth’s surface. - Which of the following is a correct unit for mass?

A) Newton

B) Kilogram

C) Meter per second squared

D) Joule

Correct Option: B

Explanation: Mass is measured in kilograms (kg). - What is the weight of an object on the surface of the Moon?

A) Less than its weight on Earth

B) Equal to its weight on Earth

C) Greater than its weight on Earth

D) Zero

Correct Option: A

Explanation: The gravitational acceleration on the Moon is less than that on Earth, so the weight of an object on the surface of the Moon is less than its weight on Earth. - Which of the following quantities is a measure of inertia?

A) Mass

B) Weight

C) Force

D) Acceleration

Correct Option: A

Explanation: Inertia is the resistance of an object to changes in its state of motion, and mass is a measure of this inertia. - An object is in free fall. What can be said about its acceleration?

A) It is zero

B) It is constant

C) It is increasing

D) It is decreasing

Correct Option: B

Explanation: In free fall, the only force acting on the object is gravity, resulting in a constant acceleration of approximately . - Which of the following statements about weight and mass is correct?

A) Weight is a scalar quantity, while mass is a vector quantity

B) Weight is measured in kilograms, while mass is measured in newtons

C) Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object

D) Weight and mass are the same physical quantity

Correct Option: C

Explanation: Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object. Weight is measured in newtons, while mass is measured in kilograms. - Which of the following statements about projectile motion is true?

A) The horizontal component of velocity changes with time

B) The vertical component of velocity remains constant

C) The acceleration is zero throughout the motion D) The motion is always in a straight line

Correct Option: B

Explanation: In projectile motion, the horizontal component of velocity remains constant, while the vertical component changes due to the influence of gravity. - What is the SI unit of weight?

A) Newton

B) Kilogram

C) Joule

D) Pascal

Correct Option: A

Explanation: Weight is a force, and its SI unit is the Newton (N). - What is the weight of an object on the surface of the Earth?

A) Same as its mass

B) Zero

C) Depends on the object’s volume

D) Depends on the object’s density

Correct Option: A

Explanation: The weight of an object on the surface of the Earth depends on its mass and the acceleration due to gravity, but it is not directly related to volume or density. - Which of the following statements about forces is incorrect?

A) Forces can change the shape of an object

B) Forces can change the speed of an object

C) Forces can change the direction of motion of an object

D) Forces can change the mass of an object

Correct Option: D

Explanation: Forces can affect the motion and shape of an object, but they do not change the mass of the object. - An object is in equilibrium. What can be said about the sum of the forces acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In equilibrium, the sum of the forces acting on an object is zero according to Newton’s first law of motion. - Which of the following is not a contact force?

A) Friction

B) Tension

C) Magnetic force

D) Gravitational force

Correct Option: D

Explanation: Contact forces require physical contact between objects, while gravitational force acts at a distance without direct contact. - An object is thrown horizontally with a certain velocity. What can be said about its vertical acceleration?

A) It is zero

B) It is non-zero

C) It increases with time

D) It decreases with time

Correct Option: A

Explanation: When an object is thrown horizontally, its initial vertical velocity component is zero if there is no vertical force acting on it. - The weight of an object on the Moon is approximately what fraction of its weight on Earth?

A) One-sixth

B) One-fourth

C) One-half

D) Equal

Correct Option: A

Explanation: The gravitational acceleration on the Moon is about one-sixth of that on Earth. Therefore, the weight of an object on the Moon is approximately one-sixth of its weight on Earth. - Which of the following statements about gravitational force is incorrect?

A) It is always attractive

B) It depends on the masses of the objects

C) It decreases with distance

D) It acts along the line joining the centers of mass of the objects

Correct Option: C

Explanation: Gravitational force decreases with distance according to the inverse square law, not just decreases with distance. - An object is thrown vertically upwards. At the highest point, its velocity is:

A) Zero

B) Same as the initial velocity

C) Double the initial velocity

D) Cannot be determined

Correct Option: A

Explanation: At the highest point, the object momentarily comes to rest before falling back down. Therefore, its velocity at that point is zero. - Which of the following statements is true regarding the acceleration due to gravity?

A) It is greater at higher altitudes

B) It is greater at lower altitudes

C) It is independent of altitude

D) It varies with the density of the medium

Correct Option: C

Explanation: The acceleration due to gravity is approximately constant at a given location and is independent of altitude. - An object is thrown horizontally with a certain velocity from a certain height. How long does it take for the object to reach the ground?

A) Depends on the horizontal velocity

B) Depends on the height

C) Same as the time taken for vertical free fall from the same height

D) Cannot be determined

Correct Option: C

Explanation: The time taken for the object to reach the ground is the same as the time taken for vertical free fall from the same height, as horizontal motion does not affect the time of descent. - An object is in equilibrium. What can be said about the net force acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In equilibrium, the net force acting on an object is zero according to Newton’s first law of motion. - Which of the following statements about satellites in orbit around the Earth is true?

A) They are stationary relative to the Earth

B) They are not affected by gravity

C) They are constantly falling towards the Earth

D) They have no velocity

Correct Option: C

Explanation: Satellites in orbit around the Earth are constantly falling towards the Earth due to gravity, but their horizontal velocity allows them to remain in orbit without crashing into the Earth’s surface. - Which of the following is a correct unit for mass?

A) Newton

B) Kilogram

C) Meter per second squared

D) Joule

Correct Option: B

Explanation: Mass is measured in kilograms (kg). - What is the weight of an object on the surface of the Moon?

A) Less than its weight on Earth

B) Equal to its weight on Earth

C) Greater than its weight on Earth

D) Zero

Correct Option: A

Explanation: The gravitational acceleration on the Moon is less than that on Earth, so the weight of an object on the surface of the Moon is less than its weight on Earth. - Which of the following quantities is a measure of inertia?

A) Mass

B) Weight

C) Force

D) Acceleration

Correct Option: A

Explanation: Inertia is the resistance of an object to changes in its state of motion, and mass is a measure of this inertia. - An object is in free fall. What can be said about its acceleration?

A) It is zero

B) It is constant

C) It is increasing

D) It is decreasing Correct Option: B

Explanation: In free fall, the only force acting on the object is gravity, resulting in a constant acceleration of approximately . - Which of the following statements about weight and mass is correct?

A) Weight is a scalar quantity, while mass is a vector quantity

B) Weight is measured in kilograms, while mass is measured in newtons

C) Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object

D) Weight and mass are the same physical quantity

Correct Option: C

Explanation: Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object. Weight is measured in newtons, while mass is measured in kilograms. - Which of the following statements about projectile motion is true?

A) The horizontal component of velocity changes with time

B) The vertical component of velocity remains constant

C) The acceleration is zero throughout the motion

D) The motion is always in a straight line

Correct Option: B

Explanation: In projectile motion, the horizontal component of velocity remains constant, while the vertical component changes due to the influence of gravity. - What is the SI unit of weight?

A) Newton

B) Kilogram

C) Joule

D) Pascal

Correct Option: A

Explanation: Weight is a force, and its SI unit is the Newton (N). - What is the weight of an object on the surface of the Earth?

A) Same as its mass

B) Zero

C) Depends on the object’s volume

D) Depends on the object’s density

Correct Option: A

Explanation: The weight of an object on the surface of the Earth depends on its mass and the acceleration due to gravity, but it is not directly related to volume or density. - Which of the following statements about forces is incorrect?

A) Forces can change the shape of an object

B) Forces can change the speed of an object

C) Forces can change the direction of motion of an object

D) Forces can change the mass of an object

Correct Option: D

Explanation: Forces can affect the motion and shape of an object, but they do not change the mass of the object. - An object is in equilibrium. What can be said about the sum of the forces acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In equilibrium, the sum of the forces acting on an object is zero according to Newton’s first law of motion. - Which of the following is not a contact force?

A) Friction

B) Tension

C) Magnetic force

D) Gravitational force

Correct Option: D

Explanation: Contact forces require physical contact between objects, while gravitational force acts at a distance without direct contact. - An object is thrown horizontally with a certain velocity. What can be said about its vertical acceleration?

A) It is zero

B) It is non-zero

C) It increases with time

D) It decreases with time

Correct Option: A

Explanation: When an object is thrown horizontally, its initial vertical velocity component is zero if there is no vertical force acting on it. - The weight of an object on the Moon is approximately what fraction of its weight on Earth?

A) One-sixth

B) One-fourth

C) One-half

D) Equal

Correct Option: A

Explanation: The gravitational acceleration on the Moon is about one-sixth of that on Earth. Therefore, the weight of an object on the Moon is approximately one-sixth of its weight on Earth. - Which of the following statements about gravitational force is incorrect?

A) It is always attractive

B) It depends on the masses of the objects

C) It decreases with distance

D) It acts along the line joining the centers of mass of the objects

Correct Option: C

Explanation: Gravitational force decreases with distance according to the inverse square law, not just decreases with distance. - An object is thrown vertically upwards. At the highest point, its velocity is:

A) Zero

B) Same as the initial velocity

C) Double the initial velocity

D) Cannot be determined

Correct Option: A

Explanation: At the highest point, the object momentarily comes to rest before falling back down. Therefore, its velocity at that point is zero. - Which of the following statements is true regarding the acceleration due to gravity?

A) It is greater at higher altitudes

B) It is greater at lower altitudes

C) It is independent of altitude

D) It varies with the density of the medium

Correct Option: C

Explanation: The acceleration due to gravity is approximately constant at a given location and is independent of altitude. - An object is thrown horizontally with a certain velocity from a certain height. How long does it take for the object to reach the ground?

A) Depends on the horizontal velocity

B) Depends on the height

C) Same as the time taken for vertical free fall from the same height

D) Cannot be determined

Correct Option: C

Explanation: The time taken for the object to reach the ground is the same as the time taken for vertical free fall from the same height, as horizontal motion does not affect the time of descent. - An object is in equilibrium. What can be said about the net force acting on it?

A) It is zero

B) It is non-zero

C) It is increasing

D) It is decreasing

Correct Option: A

Explanation: In equilibrium, the net force acting on an object is zero according to Newton’s first law of motion. - Which of the following statements about satellites in orbit around the Earth is true?

A) They are stationary relative to the Earth

B) They are not affected by gravity

C) They are constantly falling towards the Earth

D) They have no velocity

Correct Option: C

Explanation: Satellites in orbit around the Earth are constantly falling towards the Earth due to gravity, but their horizontal velocity allows them to remain in orbit without crashing into the Earth’s surface. - Which of the following is a correct unit for mass?

A) Newton

B) Kilogram

C) Meter per second squared

D) Joule

Correct Option: B

Explanation: Mass is measured in kilograms (kg). - What is the weight of an object on the surface of the Moon?

A) Less than its weight on Earth

B) Equal to its weight on Earth

C) Greater than its weight on Earth

D) Zero

Correct Option: A

Explanation: The gravitational acceleration on the Moon is less than that on Earth, so the weight of an object on the surface of the Moon is less than its weight on Earth. - Which of the following quantities is a measure of inertia?

A) Mass

B) Weight

C) Force

D) Acceleration

Correct Option: A

Explanation: Inertia is the resistance of an object to changes in its state of motion, and mass is a measure of this inertia. - An object is in free fall. What can be said about its acceleration?

A) It is zero

B) It is constant

C) It is increasing

D) It is decreasing

Correct Option: B

Explanation: In free fall, the only force acting on the object is gravity, resulting in a constant acceleration of approximately . - Which of the following statements about weight and mass is correct?

A) Weight is a scalar quantity, while mass is a vector quantity

B) Weight is measured in kilograms, while mass is measured in newtons

C) Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object

D) Weight and mass are the same physical quantity

Correct Option: C

Explanation: Weight is the force exerted on an object due to gravity, while mass is the amount of matter in an object. Weight is measured in newtons, while mass is measured in kilograms.

## Physics Class 9 MCQs Chapter wise

Engage with exclusive chapters dedicated to Class 9 Physics MCQs, systematically arranged by subject for easy reference and concentrated learning. Each chapter comprises over 1000 MCQs, offering ample practice opportunities to reinforce understanding and excel in Physics. Access MCQs corresponding to each chapter by simply selecting the provided chapter titles.

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