CBSE Class 12 Physics Important Questions with Answers – Free PDF Download for 2025

Physics in class 12 is one of the most important subject for every CBSE student. To score good marks in the CBSE Class 12 Board, students must focus on practice and revision of the right set of questions. That is why we have created a complete list of CBSE class 12 Physics Important Questions. These questions are designed according to the CBSE Syllabus Class 12 Physics and also based on NCERT books. With the help of these, students can understand the exam pattern better and prepare with more confidence.

You can also get physics important questions class 12 CBSE board pdf download and physics important questions class 12 pdf download from here, which makes study easier anytime and anywhere. We also provide important questions for class 12 physics with answers ncert, so that you can check your preparation and clear your concepts side by side. For the coming exam season, especially for important questions for physics class 12 CBSE board 2025, this resource is going to be very useful. Along with this, NCERT Solutions for Class 12 Physics are also added so that students can revise step by step.

CBSE Class 12 Physics Important Questions Chapter-wise

The CBSE Class 12 Physics Important Questions with Answers are arranged chapter-wise from all 14 chapters, allowing students to prepare in a structured way. These questions highlight the key Physics topics and make revision easier and more effective.

10 Most Important Questions From Class 12 Physics Chapters with Answer

Q1: Does the force between two point charges change if the dielectric constant of the medium is increased?

Answer: Yes. As the dielectric constant k increases, the electrostatic force decreases, since F_medium = F_vacuum / k. A larger k reduces the effective interaction between the charges.

Chapter: Electric Charges & FieldsType: Very Short Answer (1 mark)

Q2: A charged rod P attracts rod R but repels rod Q. What kind of force acts between Q and R?

Answer:Attractive. Since P repels Q (same sign) but attracts R (opposite sign or induced), Q and R must be of opposite nature relative to each other, so they attract.

Chapter: Electric Charges & FieldsType: Very Short Answer (1 mark)

Q3: Which physical quantities have SI units (i) C·m and (ii) N/C?

Answer: (i) Electric dipole moment → C·m. (ii) Electric field intensity → N/C.

Chapter: Electric Charges & FieldsType: Very Short Answer (1 mark)

Q4: Define one coulomb.

Answer: One coulomb is that charge which, when placed one metre apart from an equal like charge in vacuum, experiences a force of about 9 × 10^9 N. (Equivalent practical sense: it is the charge transported by 1 A in 1 s.)

Chapter: Electrostatic Potential & CapacitanceType: Very Short Answer (1 mark)

Q5: Why does the electric field inside a dielectric decrease when it is placed in an external field?

Answer: The molecules polarize and create an induced field opposite the external field, so the net field inside the dielectric is reduced.

Chapter: Electrostatic Potential & CapacitanceType: Very Short Answer (1 mark)

Q6: What is the work done in moving a 2 μC point charge from corner A to corner B of a square if a 10 μC charge is fixed at the centre?

Answer:Zero. Corners A and B are at the same potential with respect to the central charge, so W = q (V_B − V_A) = 0.

Chapter: Electrostatic Potential & CapacitanceType: Very Short Answer (1 mark)

Q7: If the force between two point charges at separation d is F, what separation makes the force F/3?

Answer: Increase the distance by a factor of √3: r_new = √3 · d, since F ∝ 1/r².

Chapter: Wave OpticsType: Very Short Answer (1 mark)

Q8: Draw a diagram to show a cylindrical wavefront.

Answer: (Sketch required.) Indicate a line source and draw concentric cylindrical surfaces (coaxial), each representing points of equal phase; normals to the surfaces show the propagation direction.

Chapter: Wave OpticsType: Very Short Answer (1 mark)

Q9: A light wave enters from air into glass. How are (a) the energy and (b) the frequency affected?

Answer: (a) Transmitted intensity (energy flux) generally decreases due to reflection at the boundary. (b) Frequency remains unchanged on refraction (f = constant), while wavelength changes.

Chapter: Wave OpticsType: Short Answer (3 marks)

Q10: State Brewster’s law. Prove that at the polarising angle the reflected and refracted rays are perpendicular.

Answer: Brewster’s law:tan i_p = μ, where i_p is the polarising angle and μ is the refractive index of the medium. Using Snell’s law (μ = sin i_p / sin r) and the condition for zero reflection of the parallel component, one obtains i_p + r = 90°. Hence, at Brewster’s angle the reflected and refracted rays are perpendicular.

CBSE Class 12 Physics Important Questions – Complete Guide for Students

Physics in class 12 CBSE board is not only an important subject but also a deciding factor for higher studies in engineering, medical entrance exams, and other competitive tests. Many students often feel that physics is tough because of the derivations, numericals, and conceptual theories, but with proper preparation it can become one of the easiest scoring subjects. That is why resources like CBSE class 12 Physics Important Questions are very useful for exam preparation.

At Infinity Learn, our team of teachers and subject experts have carefully designed a complete set of important questions for physics class 12 CBSE board 2025. These questions are prepared after deep research of previous year papers, NCERT textbook exercises, and based on the CBSE Syllabus Class 12 Physics. Students can also get the physics important questions class 12 CBSE board pdf download so that they can revise offline anytime.

Why Class 12 Physics is Important?

Class 12 physics is the base of many higher-level subjects in science and engineering. If you want to prepare for JEE, NEET, or other competitive exams, physics plays a key role. Even in the CBSE Class 12 Board exam, physics can help to increase your percentage if you prepare smartly.

Many times students miss out on important derivations and formulas, and they lose marks even when the question is simple. With our important questions for class 12 physics with answers NCERT, you can avoid such mistakes. These questions cover every chapter in detail and make sure you don’t skip any important topic.

The faculties at Infinity Learn are highly experienced and have cleared many national-level exams themselves. With their guidance, we bring to you the cream of important questions that are most expected in the exam.

How to Study for Class 12 Physics Effectively?

Studying physics is not about mugging formulas. It is about understanding concepts and then applying them in problems. Here are some tips:

• Go through NCERT Solutions for Class 12 Physics chapter by chapter. NCERT is the backbone for CBSE exams.
• Revise class 11 topics like Mechanics because they are connected with class 12 topics.
• Make your own physics notes. Write all important points, definitions, and derivations in one place.
• Create a separate notebook for important formulas and short tricks.
• Solve all NCERT examples and back exercise problems. Many exam questions directly come from there.
• Regularly practice the physics important questions class 12 pdf download provided by Infinity Learn.

Remember, consistency is the key. If you revise daily, physics will become easy and interesting.

Why Infinity Learn is Best for Class 12 Physics Preparation?

At Infinity Learn, we believe in simple learning with clarity. That’s why we have created a special set of Important Questions For Class 12 Physics in PDF format. This PDF can be downloaded free with just one click.

• Concise and neat format – All questions are arranged chapter-wise for quick revision.
• Detailed step-by-step solutions – Each question has a clear solution, so you can learn the method.
• Free availability – Students can download without paying any extra cost.
• Expert faculty – The content is prepared by teachers who know the CBSE pattern deeply.

Our experts are also available round-the-clock to clear doubts and help students. The goal is not just to prepare for the board exams but also to get ready for competitive exams.

CBSE Class 12 Physics Pattern

Before starting preparation, it is important to know the exam pattern.

• The physics exam usually has four sections: A, B, C, and D.
• Section A contains 1 mark questions (mostly objective type).
• Section B has 2 mark questions.
• Section C contains 3 mark questions.
• Section D has 5 mark questions (mostly derivations and numerical problems).

There is no overall choice in the paper, but internal choice is given in some questions. That means you need to prepare every topic properly.

Tips to Score Good Marks in CBSE Class 12 Physics

Here are some practical tips that can really help:

1. Know the syllabus – Start with the official CBSE Syllabus Class 12 Physics.
2. Focus on derivations – Most of the 5-mark questions are directly from NCERT derivations.
3. Practice numericals – Do not skip numerical questions; they are scoring if you know formulas.
4. Revise regularly – Don’t wait till the last month. Revise at least one chapter daily.
5. Use NCERT properly – Solve all NCERT examples, back questions, and exemplar problems.
6. Solve previous year papers – This will help you understand the trend of questions.

Chapter-wise Class 12 Physics Important Topics

Here is a chapter-wise list of important topics and subtopics:

1. Electric Charges and Fields

• Types of charges and properties
• Gauss’s Law and its applications
• Charge conservation and quantization

2. Electrostatic Potential and Capacitance

• Electrostatic potential difference
• Relationship between potential and electric field
• Capacitance and combination of capacitors

3. Current Electricity

• Drift velocity
• Ohm’s law and derivation
• Relation between current, resistance, and resistivity

4. Moving Charges and Magnetism

• Magnetic force on moving charges
• Biot-Savart’s Law
• Ampere’s Law
• Motion in combined electric and magnetic fields

5. Magnetism and Matter

• Properties of bar magnets
• Earth’s magnetism
• Magnetic field lines and properties

6. Electromagnetic Induction

• Faraday’s laws of EMI
• Lenz’s law
• Fleming’s right hand rule

7. Alternating Current

• AC applied to resistor, inductor, capacitor
• Transformers and applications
• LC oscillations

8. Electromagnetic Waves

• Maxwell’s equations
• Displacement current
• Applications of EM waves

9. Ray Optics and Optical Instruments

• Reflection and refraction of light
• Mirrors and lenses
• Optical instruments like microscope and telescope

10. Wave Optics

• Huygens’ principle
• Young’s double slit experiment
• Polarisation of light

11. Dual Nature of Radiation and Matter

• Photoelectric effect
• Wave-particle duality
• de Broglie’s explanation

12. Atoms

• Rutherford’s model
• Bohr’s model
• Atomic spectra

13. Nuclei

• Radioactivity (alpha, beta, gamma emission)
• Nuclear stability
• Binding energy per nucleon

Physics can look tough, but with the right strategy, it becomes scoring. Always start with NCERT textbook, then move to important questions for class 12 physics with answers NCERT Solutions, and finally solve sample papers. Infinity Learn is here to make your preparation easier with physics important questions class 12 pdf download and detailed NCERT Solutions for Class 12 Physics.