Welcome to our blog post with multiple-choice questions (MCQs) on Physics: Laws of Motion for Class 11 students. Dive into the world of motion and forces through these engaging questions designed to test and expand your understanding.
The Laws of Motion, introduced by Sir Isaac Newton, are rules that explain how objects move and stop. These laws help us understand why things stay still, start moving, or change direction. There are three main laws: the first one says objects like to keep doing what they’re doing unless something pushes or pulls them; the second one explains how the push or pull affects how fast things move; and the third one tells us that every action has an equal and opposite reaction.
By the end, you’ll have a better grasp of these fundamental concepts, making you more prepared for your physics class and curious about the world of motion around you. Let’s get moving and learn through these exciting questions!
1. Newton’s first law of motion is also known as:
Answer:
Explanation:
Newton’s first law states that an object will remain at rest or move in a straight line at a constant speed unless acted upon by an external force. This property is called inertia.
2. The quantity which measures an object’s resistance to change in its velocity is:
Answer:
Explanation:
Inertia is the inherent property of a body that resists changes in its state of motion.
3. If a net force acting on an object is zero, then the object:
Answer:
Explanation:
According to Newton’s first law, an object can either be at rest or move at a constant velocity when no net force acts on it.
4. Newton’s third law of motion states:
Answer:
Explanation:
This means that for every force, there is a force of equal magnitude but in the opposite direction acting on another body.
5. If you push a wall with a force of 10N, the wall pushes back with:
Answer:
Explanation:
According to Newton’s third law, every action has an equal and opposite reaction.
6. Which of the following is the correct expression for Newton’s second law?
Answer:
Explanation:
Newton’s second law states that the force acting on an object is equal to the mass of that object times its acceleration.
7. A body of mass 10 kg is moving with a constant velocity of 10 m/s. The net force acting on the body is:
Answer:
Explanation:
If the velocity is constant, it means there’s no acceleration, and hence no net force acting on the body.
8. The unit of force in SI units is:
Answer:
Explanation:
In the SI system, the unit of force is Newton (N).
9. When an object is in free fall, the only force acting on it is:
Answer:
Explanation:
In free fall, the only significant force acting on the object is the gravitational pull from the Earth.
10. An object moving in a circle at constant speed:
Answer:
Explanation:
Even if the speed is constant, the direction is changing. Hence, velocity (which has both magnitude and direction) is changing.
11. An object of mass 5 kg is accelerating at 2 m/s^2. The force exerted on the object is:
Answer:
Explanation:
Using Newton’s second law, F = ma, the force is 5 kg x 2 m/s^2 = 10 N.
12. Which of these is NOT a contact force?
Answer:
Explanation:
Magnetic force can act over a distance without direct contact, making it a non-contact force.
13. A car moving on a straight road comes to a stop after a certain distance, when its engine is switched off. This is due to:
Answer:
Explanation:
The frictional force acts opposite to the direction of motion, slowing the car down and eventually stopping it.
14. A book is resting on a table. The reaction to the Earth’s gravitational force acting on the book is:
Answer:
Explanation:
According to Newton’s third law, every action has an equal and opposite reaction. The Earth pulls the book with gravitational force, and the book also pulls the Earth with an equal and opposite gravitational force.
15. In the absence of an external force, a moving object will:
Answer:
Explanation:
According to Newton’s first law (Law of Inertia), in the absence of an external force, an object will continue in its state of motion, which can be rest or uniform motion in a straight line.