NCERT Solutions For Class 11 Physics Chapter 1 : Physical World

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NCERT Solutions for Class 11 Physics Chapter 1 Physical World deals with the matters and the materials around the world, where the laws of physics are being applied in nature. The Physical world around us is full of different complex natural phenomena. These are based on some basic physical laws that govern their working in nature. 

The chapter has been omitted from the CBSE Class 11 Physics Syllabus 2022-2023. Class 11 Physics Chapter 1 deals with the scope of physics and technology in society, gravitational force, electromagnetic force, and strong and weak nuclear force. It also covers the nature of physical laws.

Download PDF: NCERT Solutions for Class 11 Physics Chapter 1


NCERT Solutions for Class 11 Physics Chapter 1


Class 11 Physics Chapter 1 – Important Concepts 

  • Physics is a fundamental science that is concerned with understanding the natural phenomena that occur in the universe.
The various branches of Physics include – Mechanics, Thermodynamics, Electromagnetism, and Modem Physics.
  • The scope of Physics covers a magnitude of physical quantities such as mass, length, time, energy, and so on.
Physics deals with the macroscopic world such as the universe and galaxies as well as the microscopic world such as the nucleus of an atom.
  • Gravitational force is the force of attraction between any 2 bodies that is directly proportional to the product of their masses. It is inversely proportional to the square of the distance between them.
\(\begin{array}{l}F\propto \frac{(m_{1}m_{2})}{r^{2}}\end{array}\)
Electromagnetic Force can be either attractive or repulsive.
  • Nuclear force is a force that acts between the neutrons and protons of atoms.

CBSE CLASS XII Related Questions

  • 1.
    The energy of an electron in an orbit in hydrogen atom is \( -3.4 \, \text{eV} \). Its angular momentum in the orbit will be:

      • \( \dfrac{3h}{2\pi} \)
      • \( \dfrac{2h}{\pi} \)
      • \( \dfrac{h}{\pi} \)
      • \( \dfrac{h}{2\pi} \)

    • 2.
      Write any two features of nuclear forces.


        • 3.
          Suppose a pure Si crystal has \( 5 \times 10^{28} \) atoms per \( \text{m}^3 \). It is doped with \( 5 \times 10^{22} \) atoms per \( \text{m}^3 \) of Arsenic. Calculate majority and minority carrier concentration in the doped silicon. (Given: \( n_i = 1.5 \times 10^{16} \, \text{m}^{-3} \))


            • 4.
              Consider the nuclear reaction \( X \to Y + Z \). Let \( M_x \), \( M_y \), and \( M_z \) be the masses of the three nuclei X, Y, and Z respectively. Then which of the following relations hold true?

                • \( (M_x - M_z)<M_y \)
                • \( (M_x - M_y)<M_z \)
                • \( M_x>(M_y + M_z) \)
                • \( M_x<(M_y + M_z) \)

              • 5.
                Assertion : Photoelectric effect is a spontaneous phenomenon. Reason (R): According to the wave picture of radiation, an electron would take hours/days to absorb sufficient energy to overcome the work function and come out from a metal surface.

                  • Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
                  • Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
                  • Assertion (A) is true, but Reason (R) is false.
                  • Both Assertion (A) and Reason (R) are false.

                • 6.
                  Determine the current in the \( 3 \, \Omega \) branch of a Wheatstone Bridge in the circuit shown in the figure.

                    CBSE CLASS XII Previous Year Papers

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