NCERT Solutions for class 11 Physics Chapter 4: Motion in a plane

Jasmine Grover logo

Jasmine Grover Content Strategy Manager

Content Strategy Manager

The NCERT Solutions for Class 11 Physics Chapter 4 Motion in a plane are provided in the article below. The motion of a body can be referred to as its change in position depending on its surroundings in a given time interval. The motion of any object which has some mass can be measured in distance, displacement, speed and velocity, acceleration, and time.

Class 11 Physics Chapter 4 Motion in a Plane belongs to Unit 2 Kinematics which has a weightage of 23 marks along with Unit 1 Physical World and Measurement and Unit 3 Laws of Motion. NCERT Solutions for Chapter 4 Physics Class 11 deals with the concept of scalars and vectors, uniform circular motion, and relative velocity in two dimensions.

Download PDF: NCERT Solutions for Class 11 Physics Chapter 4


NCERT Solutions for Class 11 Physics Chapter 4

NCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT SolutionsNCERT Solutions

Class 11 Physics Chapter 4 – Concepts Covered

  • Motion in a plane is known as motion in two dimensions. For example, projectile motion, circular motion etc.
  • Scalar Quantities are the physical quantities that are specified by their magnitude or size alone.
Examples of Scalar Quantities – Length, mass, density, speed, work, etc
  • Vector Quantities are the physical quantities that are characterised by both magnitude and direction.
Example of Vector Quantities – Velocity, displacement, acceleration, force, momentum, torque etc.
  • A unit vector is a vector with a unit magnitude that points in a particular direction. It is used to only specify the direction.
It can be represented as \(\widehat{A} = { \overrightarrow{A} \over |\overrightarrow{A}|}\)
  • Parallelogram Law of Vector Addition: If \(\overrightarrow{A}\)and \(\overrightarrow{B}\) are the two adjacent sides of a parallelogram, inclined at an angle \(\theta\), then the magnitude of resultant vector is determined.

\(R = \sqrt{A^2 + B^2 +2ABcos\theta}\)

  • The projectile is an initial inclined velocity which subsequently follows a path determined by the gravitational force that acts on it and by the frictional resistance of the air.
  • The path followed by a projectile is known as its trajectory.

CBSE CLASS XII Related Questions

  • 1.
    A system of two conductors is placed in air and they have net charge of \( +80 \, \mu C \) and \( -80 \, \mu C \) which causes a potential difference of 16 V between them.
    (1) Find the capacitance of the system.
    (2) If the air between the capacitor is replaced by a dielectric medium of dielectric constant 3, what will be the potential difference between the two conductors?
    (3) If the charges on two conductors are changed to +160µC and −160µC, will the capacitance of the system change? Give reason for your answer.


      • 2.
        The electric field at a point in a region is given by \( \vec{E} = \alpha \frac{\hat{r}}{r^3} \), where \( \alpha \) is a constant and \( r \) is the distance of the point from the origin. The magnitude of potential of the point is:

          • \( \frac{\alpha}{r} \)
          • \( \frac{\alpha r^2}{2} \)
          • \( \frac{\alpha}{2r^2} \)
          • \( -\frac{\alpha}{r} \)

        • 3.
          A rectangular glass slab ABCD (refractive index 1.5) is surrounded by a transparent liquid (refractive index 1.25) as shown in the figure. A ray of light is incident on face AB at an angle \(i\) such that it is refracted out grazing the face AD. Find the value of angle \(i\).
          A rectangular glass slab ABCD (refractive index 1.5)


            • 4.
              Write the mathematical forms of three postulates of Bohr’s theory of the hydrogen atom. Using them prove that, for an electron revolving in the \( n \)-th orbit,
              (a) the radius of the orbit is proportional to \( n^2 \), and
              (b) the total energy of the atom is proportional to \( \frac{1}{n^2} \).


                • 5.
                  (a) Consider the so-called ‘D-T reaction’ (Deuterium-Tritium reaction).
                  In a thermonuclear fusion reactor, the following nuclear reaction occurs: \[ \ ^{2}_1 \text{H} + \ ^{3}_1 \text{H} \longrightarrow \ ^{4}_2 \text{He} + \ ^{1}_0 \text{n} + Q \] Find the amount of energy released in the reaction.
                  % Given data Given:
                  \( m\left(^{2}_1 \text{H}\right) = 2.014102 \, \text{u} \)
                  \( m\left(^{3}_1 \text{H}\right) = 3.016049 \, \text{u} \)
                  \( m\left(^{4}_2 \text{He}\right) = 4.002603 \, \text{u} \)
                  \( m\left(^{1}_0 \text{n}\right) = 1.008665 \, \text{u} \)
                  \( 1 \, \text{u} = 931 \, \text{MeV}/c^2 \)


                    • 6.
                      A vertically held bar magnet is dropped along the axis of a copper ring having a cut as shown in the diagram. The acceleration of the falling magnet is:
                      vertically held bar magnet is dropped along the axis of a copper ring

                        • zero
                        • less than \( g \)
                        • \( g \)
                        • greater than \( g \)
                      CBSE CLASS XII Previous Year Papers

                      Comments


                      No Comments To Show