Motion in a Plane MCQ Class 11 Physics

MCQs (Multiple Choice Questions) are a vital part of exam preparation, especially for competitive exams and board assessments. They help students grasp important concepts quickly, identify learning gaps, and practice effectively. Solving motion in a plane class 11 MCQ ensures you are well-prepared to tackle challenging questions.

Motion in a Plane MCQs are an important tool for Class 11 Physics as they simplify complex topics like Motion in a Plane and Laws of Motion into smaller, easy-to-understand parts. These Class 11 Physics mcq questions help students prepare for school exams, competitive tests like NEET and JEE, and class quizzes by focusing on key concepts and their real-world applications.

The chapter Motion in a Plane covers topics like vectors, velocity, acceleration, and relative motion, essential for understanding two-dimensional motion. With resources like Motion in a Plane Class 11 MCQ PDFs, solutions for step-by-step guidance, and interactive quiz questions, students can strengthen their fundamentals and practice effectively to excel in Physics.

Class 11 Physics Motion in a Plane Overview

Class 11 Physics chapter 4 Motion in a Plane focuses on the study of the motion of objects in two dimensions, including both position and velocity in a plane. It builds on the concepts of kinematics and introduces the mathematical framework required to describe and analyze motion that occurs in more than one direction simultaneously.

Vectors and Scalars:

• Scalars: Physical quantities that are described by a magnitude alone (e.g., temperature, mass, distance).
• Vectors: Quantities that have both magnitude and direction (e.g., displacement, velocity, force). Vectors are represented graphically as arrows, and vector operations (addition, subtraction, and multiplication) are fundamental for solving problems in motion in a plane.

Position, Displacement, and Velocity:

• Position: The location of an object in space, defined by coordinates (x, y) in the plane.
• Displacement: A vector quantity that refers to the change in position, pointing from the initial position to the final position.
• Velocity: A vector quantity describing the rate of change of displacement. Average velocity is calculated as the displacement divided by time, while instantaneous velocity is the rate of change of position at any given point in time.

Acceleration:

• Acceleration in Two Dimensions: The rate of change of velocity with respect to time. It has both magnitude and direction and is represented as a vector.
• Components of acceleration can be found using vector decomposition into horizontal and vertical directions.

Projectile Motion:

• Projectile: An object that is thrown or projected into the air and influenced only by the force of gravity (neglecting air resistance).
• Trajectory: The path followed by a projectile, which is a parabola in ideal conditions.
• The horizontal and vertical motions of a projectile are analyzed separately:
• • 1. Horizontal Motion: Uniform motion with constant velocity (no acceleration).
    2. Vertical Motion: Accelerated motion under the influence of gravity (with acceleration
       $g = 9.8 m/s^2$

       g=9.8m/s2).

Relative Motion:

• The concept of relative velocity helps understand how an object’s motion is observed from different reference frames. The velocity of an object relative to another is computed as the difference between their individual velocities.

Circular Motion:

• Motion of an object moving along the circumference of a circle, characterized by centripetal acceleration and centripetal force.
• Angular displacement, angular velocity, and angular acceleration are the key quantities to describe rotational motion.

Class 11 Physics Motion in a Plane MCQ Questions and Answers

Question 1: Which among the following is a scalar quantity?

a) Force

b) Mass

c) Momentum

d) Velocity

Answer: b) Mass

Explanation: A scalar quantity is defined as having only magnitude without any direction. Mass fits this definition as it represents the amount of matter in an object and does not depend on direction, unlike force, momentum, and velocity.

Question 2: State true or false: A vector quantity obeys the triangle law of addition.

a) True

b) False

Answer: a) True

Explanation: Vector quantities have both magnitude and direction. They follow specific rules for addition, such as the triangle law and parallelogram law, which help determine the resultant of two or more vectors graphically.

Question 3: Which is the vector that gives the position of a point with reference to a point other than the origin of the coordinate system?

a) Coplanar Vectors

b) Equal vector

c) Unit Vector

d) Displacement vector

Answer: d) Displacement vector

Explanation: A displacement vector represents the shortest path between two points, showing the change in position with both magnitude and direction. It can be referenced from any point in the coordinate system, not necessarily the origin.

Question 4: Which theorem states that “If a particle under the simultaneous action of three forces is in equilibrium, then each force has a constant ratio with the sine of the angle between the other two forces”?

a) Lay’s theorem

b) Lami’s Theorem

c) Newton’s law

d) Faraday’s theorem

Answer: b) Lami’s Theorem

Explanation: Lami’s Theorem is a principle in physics that applies to a particle in equilibrium under three forces. It states that the ratio of each force to the sine of the angle opposite it is constant. This theorem is frequently used in problems involving concurrent forces.

Question 5: Vectors lying in the same or parallel to the same plane are called ————–

a) Coplanar vectors

b) Equal vector

c) Unit Vector

d) Displacement vector

Answer: a) Coplanar vectors

Explanation: Coplanar vectors are vectors that lie in the same plane or are parallel to a common plane. This property is important in analyzing systems with forces or motions confined to two dimensions.

Question 6: Dot product is distributive; it is given as:

a) A.(B-C) = A.B*A.C

b) A.(B+C) = A.B-A.C

c) A.(B+C) = A.B+A.C

d) A.(B*C) = A.B/A.C

Answer: c) A.(B+C) = A.B+A.C

Explanation: The dot product of vectors follows the distributive property, which means that the scalar product of a vector with the sum of two vectors equals the sum of their individual dot products. This property simplifies calculations involving multiple vectors.

Question 7: Uniform circular motion is given by the formula:

a)

$v = \omega r$

v=ωr

b)

$v = \omega + r$

v=ω+r

c)

$v = \omega – r$

v=ω−r

d)

$v = \omega / r$

v=ω/r

Answer: a)

$v = \omega r$

v=ωr

Explanation: In uniform circular motion, the speed of an object moving in a circular path at a constant angular velocity (

$\omega$

ω) is related to the radius (

$r$

r) of the circle by the formula

$v = \omega r$

v=ωr. This formula is essential for analyzing circular motion dynamics.

Question 8: Motion in a plane is called _________________

a) Motion in one dimension

b) Motion in two dimensions

c) Motion in three dimensions

d) Motion in four dimensions

Answer: b) Motion in two dimensions

Explanation: When an object’s motion is confined to a plane, it is referred to as motion in two dimensions. Examples include the trajectory of a projectile or the motion of a car turning along a flat road.

Question 9: The minimum number of vectors of equal magnitude required to produce a zero resultant is:

a) 2

b) 3

c) 4

d) More than 4

Answer: (b) 3

Explanation: To produce a zero resultant, the vectors must form a closed polygon when arranged head to tail. The minimum number of equal magnitude vectors required to form such a closed figure is three, forming an equilateral triangle.

Question 10: The resultant of two forces, one double the other in magnitude, is perpendicular to the smaller of the two forces. Find the angle between the forces:

a) 150°

b) 120°

c) 90°

d) 60°

Answer: (b) 120°

Explanation: When the resultant is perpendicular to the smaller force, the angle between the two forces can be calculated using trigonometric relations. For one force double the other, the angle is 120°.

Question 11: Which pair of the following forces will never give a resultant force of 2 N?

a) 2 N and 2 N

b) 1 N and 1 N

c) 1 N and 3 N

d) 1 N and 4 N

Answer: (d) 1 N and 4 N

Explanation: The resultant of two forces lies between the sum and the difference of their magnitudes. For 1 N and 4 N, the resultant can range from 3 N to 5 N but can never be 2 N.

FAQs on Motion in a Plane MCQ Class 11 Physics

Why should I solve MCQs for Motion in a Plane?

Solving MCQs helps you test your understanding of key concepts like vectors, projectile motion, and relative velocity. It allows you to practice applying formulas and solving problems quickly, which is crucial for exams like JEE and NEET. Additionally, MCQs enhance your ability to recall formulas and concepts under time pressure, improving your overall performance.

How do MCQs help in revising the concepts of Motion in a Plane?

MCQs provide a focused way to revise important concepts, helping you recognize which areas need more attention. By solving different types of questions, you can identify gaps in your understanding and address them before the actual exam. This active recall process strengthens your memory and boosts retention of key formulas and principles.

Can solving MCQs improve my speed and accuracy for exams?

Yes, solving MCQs regularly helps you improve both speed and accuracy. As you practice more, you become familiar with the types of questions typically asked, which reduces the time spent on understanding the question during exams. Additionally, regular practice sharpens your problem-solving approach, helping you avoid common mistakes and boost your accuracy.

What should I focus on while solving MCQs for Motion in a Plane?

While solving MCQs, focus on understanding the underlying concepts rather than just memorizing formulas. Pay attention to the vector components, the relationships between horizontal and vertical motions in projectile motion, and how relative velocity affects the movement of objects. Carefully read each question and analyze the options before selecting the answer to ensure accuracy.