CBSE Class XII Physics Important Questions 2026 – Complete Guide

Introduction

This comprehensive guide covers the most important questions for CBSE Class XII Physics examination 2026. These questions have been carefully selected based on previous years’ papers and latest examination patterns.

Chapter-wise Important Questions

Unit I: Electrostatics

Very Short Answer Questions (1 Mark):

• Define electric dipole moment.
• What is Gauss’s law in electrostatics?
• State the principle of superposition of electric charges.

Short Answer Questions (2-3 Marks):

• Derive the expression for electric field due to an electric dipole at a point on its axis.
• Explain the concept of electric potential and potential difference.
• A parallel plate capacitor is charged by connecting it to a battery. What happens to the charge, potential difference, and energy stored when a dielectric material is introduced between the plates?

Long Answer Questions (5 Marks):

• Derive Gauss’s law from Coulomb’s law. Give two applications of Gauss’s law.
• Derive the expression for capacitance of a parallel plate capacitor with and without dielectric.

Unit II: Current Electricity

Very Short Answer Questions (1 Mark):

• Define drift velocity of electrons.
• What is the SI unit of resistivity?
• State Kirchhoff’s voltage law.

Short Answer Questions (2-3 Marks):

• Establish the relation between current and drift velocity.
• Explain the principle of Wheatstone bridge.
• Define temperature coefficient of resistance. How does resistance of metals and semiconductors vary with temperature?

Long Answer Questions (5 Marks):

• Derive the expression for current in terms of drift velocity.
• Describe the working principle of a potentiometer. How is it used to compare EMF of two cells?

Unit III: Magnetic Effects of Current

Very Short Answer Questions (1 Mark):

• Define magnetic dipole moment.
• What is the SI unit of magnetic flux?
• State Ampere’s circuital law.

Short Answer Questions (2-3 Marks):

• Derive the expression for magnetic field at the center of a circular current loop.
• Explain the working of a cyclotron.
• What is magnetic susceptibility? How is it related to relative permeability?

Long Answer Questions (5 Marks):

• Derive the expression for force between two parallel current-carrying conductors.
• Describe the construction and working of a moving coil galvanometer.

Unit IV: Electromagnetic Induction

Very Short Answer Questions (1 Mark):

• State Faraday’s laws of electromagnetic induction.
• Define self-inductance.
• What is Lenz’s law?

Short Answer Questions (2-3 Marks):

• Explain the phenomenon of electromagnetic induction.
• Define mutual inductance. Derive its expression for two coaxial solenoids.
• What is eddy current? Give two applications.

Long Answer Questions (5 Marks):

• Derive the expression for EMF induced in a conductor moving in a magnetic field.
• Describe the construction and working of AC generator.

Unit V: Alternating Current

Very Short Answer Questions (1 Mark):

• Define RMS value of alternating current.
• What is power factor?
• Define reactance.

Short Answer Questions (2-3 Marks):

• Derive the expression for impedance in LCR series circuit.
• Explain resonance in LCR series circuit.
• What is transformer? State its principle.

Long Answer Questions (5 Marks):

• Derive the expression for current in LCR series circuit.
• Describe the construction and working of a transformer.

Unit VI: Electromagnetic Waves

Very Short Answer Questions (1 Mark):

• What is electromagnetic spectrum?
• Name the scientist who predicted electromagnetic waves.
• Write the relation between electric and magnetic field vectors in electromagnetic waves.

Short Answer Questions (2-3 Marks):

• List the properties of electromagnetic waves.
• Arrange the following in increasing order of wavelength: X-rays, microwaves, gamma rays, radio waves.
• Write Maxwell’s equations and explain their significance.

Unit VII: Optics

Very Short Answer Questions (1 Mark):

• Define critical angle.
• What is polarization of light?
• State Huygens’ principle.

Short Answer Questions (2-3 Marks):

• Derive the laws of refraction using Huygens’ principle.
• Explain the phenomenon of total internal reflection.
• What is optical fiber? Mention two applications.

Long Answer Questions (5 Marks):

• Derive lens formula and magnification for a thin convex lens.
• Describe Young’s double slit experiment to demonstrate interference of light.

Unit VIII: Dual Nature of Matter

Very Short Answer Questions (1 Mark):

• State de Broglie hypothesis.
• Define work function.
• What is threshold frequency?

Short Answer Questions (2-3 Marks):

• Explain photoelectric effect. State Einstein’s photoelectric equation.
• Write the properties of photons.
• Derive the expression for de Broglie wavelength.

Long Answer Questions (5 Marks):

• Describe Einstein’s explanation of photoelectric effect.
• Explain Davisson-Germer experiment.

Unit IX: Atoms and Nuclei

Very Short Answer Questions (1 Mark):

• Define binding energy.
• What is radioactive decay?
• Define half-life period.

Short Answer Questions (2-3 Marks):

• Describe Rutherford’s atomic model and its limitations.
• Explain the concept of nuclear fission and fusion.
• Write the properties of alpha, beta, and gamma radiations.

Long Answer Questions (5 Marks):

• Derive the relation between decay constant and half-life.
• Describe Bohr’s model of hydrogen atom.

Unit X: Electronic Devices

Very Short Answer Questions (1 Mark):

• What is a p-n junction?
• Define barrier potential.
• What is doping in semiconductors?

Short Answer Questions (2-3 Marks):

• Explain the formation of p-n junction and barrier potential.
• Describe the working of LED and photodiode.
• What is logic gate? Draw truth table for AND, OR, and NOT gates.

Long Answer Questions (5 Marks):

• Explain the working of npn and pnp transistors.
• Describe the construction and working of solar cell.

Important Numerical Problems

Electrostatics:

• Calculate electric field and potential at various points due to point charges and dipoles
• Problems on capacitor combinations and energy storage

Current Electricity:

• Circuit analysis using Kirchhoff’s laws
• Problems on Wheatstone bridge and potentiometer

Magnetism:

• Calculate magnetic field due to current-carrying conductors
• Problems on motion of charged particles in magnetic field

Electromagnetic Induction:

• Calculate induced EMF and current in various situations
• Problems on self and mutual inductance

AC Circuits:

• Calculate impedance, current, and power in LCR circuits
• Problems on resonance and power factor

Optics:

• Ray optics problems using lens and mirror formulas
• Wave optics problems on interference and diffraction

Modern Physics:

• Problems on photoelectric effect and de Broglie wavelength
• Nuclear physics calculations on binding energy and radioactive decay

Exam Strategy Tips

Time Management:

• Allocate time based on marks: 1 mark = 1.5 minutes, 2-3 marks = 4-5 minutes, 5 marks = 10-12 minutes
• Start with questions you’re most confident about
• Keep 10-15 minutes for revision

Answer Writing Technique:

• Write relevant formula first
• Show step-by-step calculation
• Write units and significant figures correctly
• Draw neat diagrams where required

Important Points to Remember:

• Learn all important formulas and constants
• Practice numerical problems regularly
• Understand concepts rather than rote learning
• Solve previous years’ question papers
• Focus on derivations and their applications

Conclusion

This guide covers all the essential topics and question patterns for CBSE Class XII Physics 2026. Regular practice of these questions along with thorough understanding of concepts will help students achieve excellent results in their examinations.

Best wishes for your Physics examination!