NCERT Solutions For Class 12 Physics Chapter 3: Current Electricity

Jasmine Grover logo

Jasmine Grover

Education Journalist | Study Abroad Strategy Lead

NCERT Solutions for Class 12 Physics Chapter 3 Current Electricity are given in this article. Current electricity is the electricity that powers our homes and electrical devices. Current electricity is named for the way electrons move. They “flow” in one direction- like a river current. The study of electrons in motion like this is called Electrodynamics. 

The chapter along with the unit Electrostatics has a weightage of 16 marks in CBSE Class 12 Physics exams. The NCERT Solutions for Class 12 Physics Chapter 3 covers concepts of electric current, Ohm’s law, emf, cells in series and parallel, Kirchhoff’s Rules, etc.

Download PDF: NCERT Solutions for Class 12 Physics Chapter 3


NCERT Solutions for Class 12 Physics Chapter 3

The NCERT Solutions for class 12 physics chapter 3: Current Electricity is as given below. 

NCERT SolutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solutionNCERT solution

People Also searched for : 

  1. In a potentiometer experiment, when three cells A,B, and C  are connected in series…..[KEAM]
  2. When two resistances  R1 and  R2 are connected in series, they consume 12W  power….[KEAM]
  3. Nichrome is used as electrical heating element because of its[KEAM]
  4. In the figure shown below, the terminal voltage across  E2 is[KEAM]
  5. In a potentiometer of wire length ll, a cell of emf V  is balanced at a...[KEAM]

Chapter 3 Physics Class 12 Important Topics

  • Current electricity is the flow of electrons from one section of the circuit to the another.

There are two types of Current Electricity – 

  1. Direct Current is the current electricity whose direction stays the same. It is the constant flow of electrons from a high electron density region to a region of low electron density.
  2. Alternating Current is the current electricity that keeps changing the direction of the charge flow.
  • When 2 bodies at different potentials are linked with a wire, the free electrons move from Point 1 to Point 2, until both objects reach the same potential. The current stops flowing after that.
  • Electromotive Force: Electromotive force is the electric potential that is either produced by an electrochemical cell or produced by changing the magnetic field.
  • Voltage: Voltage is the electric potential difference between any two points.
    Ohm’s Law states that the electric current flowing through a conductor is directly proportional to the potential difference (V) applied across its ends.

It can be represented as

V = IR

The formula of electrical resistance is R = V/l.

Electrical resistance of a conductor R = ρl/A

where l = length of the conductor,

A = cross-section area, and

ρ = resistivity of the material of a conductor.

  • The current electricity can be generated through various methods.
    • Both alternating and direct current can be generated by moving a metal wire through a magnetic field.
    • Direct Current can be generated by a battery through chemical reactions.

Also Read:

Check-Out: 

CBSE CLASS XII Related Questions

  • 1.
    A square loop of side 0.50 m is placed in a uniform magnetic field of 0.4 T perpendicular to the plane of the loop. The loop is rotated through an angle of 60° in 0.2 s. The value of emf induced in the loop will be:

      • 5 V
      • 3.5 V
      • 2.5 V
      • Zero V

    • 2.
      The magnetic field in a plane electromagnetic wave travelling in glass (\( n = 1.5 \)) is given by \[ B_y = (2 \times 10^{-7} \text{ T}) \sin(\alpha x + 1.5 \times 10^{11} t) \] where \( x \) is in metres and \( t \) is in seconds. The value of \( \alpha \) is:

        • \( 0.5 \times 10^3 \, \text{m}^{-1} \)
        • \( 6.0 \times 10^2 \, \text{m}^{-1} \)
        • \( 7.5 \times 10^2 \, \text{m}^{-1} \)
        • \( 1.5 \times 10^3 \, \text{m}^{-1} \)

      • 3.
        Four long straight thin wires are held vertically at the corners A, B, C and D of a square of side \( a \), kept on a table and carry equal current \( I \). The wire at A carries current in upward direction whereas the current in the remaining wires flows in downward direction. The net magnetic field at the centre of the square will have the magnitude:

          • \( \dfrac{\mu_0 I}{\pi a} \) and directed along OC
          • \( \dfrac{\mu_0 I}{\pi a \sqrt{2}} \) and directed along OD
          • \( \dfrac{\mu_0 I \sqrt{2}}{\pi a} \) and directed along OB
          • \( \dfrac{2\mu_0 I}{\pi a} \) and directed along OA

        • 4.
          A circular coil of 100 turns and radius \( \left(\frac{10}{\sqrt{\pi}}\right) \, \text{cm}\) carrying current of \( 5.0 \, \text{A} \) is suspended vertically in a uniform horizontal magnetic field of \( 2.0 \, \text{T} \). The field makes an angle \( 30^\circ \) with the normal to the coil. Calculate:
          the magnetic dipole moment of the coil, and
          the magnitude of the counter torque that must be applied to prevent the coil from turning.


            • 5.

              The electric potential (V ) and electric field (⃗ E) are closely related concepts in electrostatics. The electric field is a vector quantity that represents the

                • Production of AC is economical.
                • AC can be easily and efficiently converted from one voltage to another.
                • AC can be transmitted economically over long distances.
                • AC is less dangerous.

              • 6.
                Nuclides with the same number of neutrons are called:

                  • Isobars
                  • Isotones
                  • Isotopes
                  • Isomers
                CBSE CLASS XII Previous Year Papers

                Comments


                No Comments To Show