ISC 2026 Physics Question Paper for Class 12

About this paper

This is ISC Class 12 Physics Paper 1 (Theory), set by CISCE for the 2026 board examination (paper code 861A). It carries 70 marks, runs for three hours plus fifteen minutes of reading time, and has 20 compulsory questions in four sections, with internal choices in two questions each in Sections B, C and D. Section A has seven multiple-choice items, including one on an electric eel's power output and one assertion–reason item, followed by seven very short answers. Section C includes a case on two students' interference and diffraction patterns, and Section D ends with a scenario-based question about a student building and testing a p-n junction diode and rectifier. A list of useful constants and relations is printed at the end, and a simple scientific calculator is allowed.

Exam

ISC Class 12

Subject

Physics

Year

2026

Paper code

861A

Maximum marks

70

Time allowed

3 hours + 15 min reading

Questions

20

Pages

12

Answers included

No, questions only

Paper pattern

• Section A

  14 marks

  Question 1 with 14 one-mark parts: 7 multiple-choice (one assertion–reason) and 7 very short answers

• Section B

  14 marks

  Questions 2–8, two marks each; internal choice in two questions

• Section C

  27 marks

  Questions 9–17, three marks each; internal choice in two questions

• Section D

  15 marks

  Questions 18–20, five marks each, ending with a scenario-based question on semiconductor diodes; internal choice in two questions

Topics covered

• Electric flux and electric dipole
• Capacitors
• Current electricity, Wheatstone bridge and cells
• Moving charges and magnetism
• Magnetic properties of materials
• Alternating current and self-inductance
• Electromagnetic waves
• Ray optics, prisms and optical instruments
• Wave optics, interference and diffraction
• Photoelectric effect and matter waves
• Bohr model and nuclear physics
• Semiconductor diodes and rectifiers

Questions from this paper

1. Calculate the momentum of a photon having an energy of 4.8 × 10⁻¹⁹ J.
2. The work functions of metals M₁ and M₂ are 1.9 eV and 5.0 eV respectively. Perform the necessary calculations to find which metal emits photoelectrons when monochromatic light of wavelength 410 nm is incident on them.
3. Using Huygens' wave theory and a labelled diagram, show that the angle of reflection is equal to the angle of incidence.
4. When a coil is connected to a 200 V dc supply the current through it is 1 A, but on a 200 V, 50 Hz ac supply the current is 0.5 A. Explain why the current is smaller on the ac supply and calculate the coefficient of self-inductance of the coil.
5. Calculate the minimum energy a gamma-ray photon must have in order to produce a proton–antiproton pair.
6. Draw a labelled diagram of an astronomical telescope when its final image lies at infinity.