The CBSE Class 12 Physics Question Paper 2025 plays a crucial role for students preparing for their board examinations. Physics is a conceptual and numerical-based subject that requires a deep understanding of topics like Electrostatics, Current Electricity, Magnetism, Optics, and Modern Physics.
In this post, we provide the important questions and their detailed answers based on the latest CBSE Class 12 Physics 2025 syllabus. These questions are designed according to the CBSE Board Exam pattern, helping students to practice effectively and gain confidence before the final examination.
CBSE Class 12 Physics Question Paper 2025 – Important Questions with Answers | Complete Exam Guide
Question 1:
What is the principle of a transformer?
Answer:
A transformer works on the principle of mutual induction, where a changing current in one coil induces an electromotive force (EMF) in another coil kept nearby. It is used to step up or step down alternating voltage.
Question 2:
State Ohm’s Law.
Answer:
Ohm’s Law states that the current flowing through a conductor is directly proportional to the potential difference across its ends, provided the temperature and other physical conditions remain constant.
Mathematically, V = IR.
Question 3:
What is the unit of magnetic flux?
Answer:
The SI unit of magnetic flux is the Weber (Wb). One Weber is equal to the magnetic flux through a surface of one square meter placed perpendicular to a magnetic field of one Tesla.
Question 4:
Define capacitance and its SI unit.
Answer:
Capacitance is the ability of a conductor to store electric charge. It is defined as the ratio of the charge (Q) on the conductor to the potential (V) developed across it.
Mathematically, C = Q/V.
The SI unit of capacitance is Farad (F).
Question 5:
What is the principle of a potentiometer?
Answer:
The potentiometer works on the principle that the potential difference across a uniform wire is directly proportional to its length, provided the current through the wire remains constant.
Question 6:
Explain the term “photoelectric effect.”
Answer:
The photoelectric effect is the emission of electrons from a metal surface when light of suitable frequency falls on it. The emitted electrons are called photoelectrons. This phenomenon supports the particle nature of light.
Question 7:
What is the difference between an AC and DC current?
Answer:
AC (Alternating Current) changes its direction and magnitude periodically, whereas DC (Direct Current) flows in one direction with a constant magnitude. AC is used in household supply, while DC is used in batteries.
Question 8:
What is the function of a rectifier?
Answer:
A rectifier converts alternating current (AC) into direct current (DC). It is commonly used in power supplies of electronic devices.
Question 9:
State the principle of a galvanometer.
Answer:
A galvanometer works on the principle that a current-carrying coil placed in a magnetic field experiences a torque, which causes the coil to deflect. The deflection is proportional to the current.
Question 10:
What is the role of a fuse in an electric circuit?
Answer:
A fuse protects electrical appliances from overcurrent or short circuits. When excessive current flows, the fuse wire melts, breaking the circuit and preventing damage.
Question 11:
Define half-life in radioactivity.
Answer:
Half-life is the time required for half the atoms of a radioactive substance to disintegrate. It is a constant for a given radioactive element.
Question 12:
What is electromagnetic induction?
Answer:
Electromagnetic induction is the process of generating an electromotive force (EMF) in a conductor due to a changing magnetic field. It was discovered by Michael Faraday.
Question 13:
What is the refractive index of a medium?
Answer:
The refractive index is the ratio of the speed of light in vacuum to the speed of light in the medium.
Mathematically, n = c/v, where c is the speed of light in vacuum and v in the medium.
Question 14:
Explain the working of a convex lens.
Answer:
A convex lens converges parallel rays of light passing through it to a single point called the principal focus. It is used in magnifying glasses and cameras.
Question 15:
What is the difference between interference and diffraction?
Answer:
Interference occurs due to the superposition of two or more coherent waves, while diffraction occurs when a wave passes through a narrow slit or around an obstacle and spreads out.
Question 16:
Define electric field intensity.
Answer:
Electric field intensity at a point is the force experienced by a unit positive charge placed at that point in an electric field.
Mathematically, E = F/q.
Question 17:
What is the use of a Zener diode?
Answer:
A Zener diode is used for voltage regulation. It allows current to flow in the reverse direction when the voltage exceeds a specific value known as the Zener breakdown voltage.
Question 18:
What are semiconductors?
Answer:
Semiconductors are materials whose conductivity lies between that of conductors and insulators. Common examples include silicon (Si) and germanium (Ge).
Question 19:
What is the relation between current and drift velocity?
Answer:
The electric current (I) in a conductor is related to drift velocity (vd) by the equation:
I = neAvd,
where n is the number of electrons per unit volume, e is the charge of an electron, and A is the cross-sectional area.
Question 20:
State Coulomb’s law.
Answer:
Coulomb’s law states that the electrostatic force between two point charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.
Mathematically, F = k(q₁q₂/r²).
Conclusion-CBSE Class 12 Physics Question Paper 2025
The CBSE Class 12 Physics Question Paper 2025 focuses on conceptual understanding and numerical problem-solving. Students are advised to practice these important questions, revise the derivations, and solve sample papers regularly. This will help improve accuracy and confidence in the final board examination.
FAQs-CBSE Class 12 Physics Question Paper 2025
Q1. What is the total marks of CBSE Class 12 Physics 2025 exam?
The CBSE Class 12 Physics exam carries 70 marks for theory and 30 marks for practicals, making a total of 100 marks.
Q2. What is the duration of the CBSE Class 12 Physics exam?
The exam duration is 3 hours.
Q3. Which chapters have the highest weightage in CBSE Class 12 Physics 2025?
Chapters like Electrostatics, Current Electricity, Optics, and Modern Physics have the highest weightage.
Q4. How many sections are there in the Physics paper?
There are usually five sections (A to E) including very short, short, and long answer-type questions.
Q5. Is numerical practice important for Physics Class 12?
Yes, numericals are very important since they test conceptual clarity and application of formulas.
Q6. Will CBSE provide choices in the question paper?
Yes, the 2025 paper is expected to include internal choices in several questions.
Q7. What is the difficulty level of CBSE Physics 2025 paper?
The paper is expected to be of moderate difficulty, focusing on understanding and application.
Q8. How can I score 90+ marks in Physics Class 12?
Focus on NCERT concepts, derivations, numerical problems, and previous year papers for consistent practice.
Q9. Are derivations compulsory in the exam?
Yes, derivations form an essential part of long-answer questions and carry significant marks.
Q10. What type of questions are asked in Section A of the Physics paper?
Section A generally contains very short answer (VSA) and objective-type questions.