The Bihar Board Class 12 Physics Model Paper 2025 plays a very important role for students preparing for their upcoming board examination. Physics is one of the most scoring yet conceptual subjects in the Science stream, and solving model papers helps students understand the exam pattern, marking scheme, and the type of questions asked.This model paper is designed according to the latest Bihar Board Class 12 Physics Model Paper 2025 and includes 35 objective questions, 7 short answer questions, and 2 long answer questions with solutions. By practicing these questions, students can strengthen their conceptual clarity, improve speed and accuracy, and boost confidence for the final exam.

Table of Contents

Bihar Board Class 12 Physics Model Paper 2025 | Question Paper with Answers

Bihar Board Class 12 Physics Model Paper 2025

Subject: Physics
Class: 12th (Intermediate)
Board: Bihar School Examination Board (BSEB)
Maximum Marks: 70
Time: 3 Hours

General Instructions

All questions are compulsory.
The question paper consists of three sections: A, B, and C.
Use of calculator is not allowed.
Draw neat and labelled diagrams wherever necessary.
Answers should be precise and to the point.

Section A: Objective Type Questions (1 × 35 = 35 Marks)

Q1. The unit of electric current is –
(a) Volt
(b) Ampere
(c) Ohm
(d) Coulomb
Answer: (b) Ampere

Q2. The value of acceleration due to gravity on Earth is approximately –
(a) 9.8 m/s²
(b) 6.67 × 10⁻¹¹ m/s²
(c) 3 × 10⁸ m/s²
(d) 1.6 × 10⁻¹⁹ m/s²
Answer: (a) 9.8 m/s²

Q3. The SI unit of resistance is –
(a) Joule
(b) Ohm
(c) Watt
(d) Tesla
Answer: (b) Ohm

Q4. Which of the following is a vector quantity?
(a) Speed
(b) Mass
(c) Work
(d) Acceleration
Answer: (d) Acceleration

Q5. Ohm’s Law is expressed as –
(a) V = IR
(b) V = I/R
(c) P = VI
(d) Q = It
Answer: (a) V = IR

Q6. Which of the following has no charge?
(a) Proton
(b) Electron
(c) Neutron
(d) Positron
Answer: (c) Neutron

Q7. The SI unit of Power is –
(a) Joule
(b) Watt
(c) Coulomb
(d) Tesla
Answer: (b) Watt

Q8. Which device is used to convert AC into DC?
(a) Inductor
(b) Transformer
(c) Rectifier
(d) Capacitor
Answer: (c) Rectifier

Q9. The speed of light in vacuum is –
(a) 3 × 10⁸ m/s
(b) 9.8 m/s
(c) 6.67 × 10⁻¹¹ m/s
(d) 1.6 × 10⁻¹⁹ m/s
Answer: (a) 3 × 10⁸ m/s

Q10. The SI unit of pressure is –
(a) Watt
(b) Pascal
(c) Newton
(d) Joule
Answer: (b) Pascal

Q11. The reciprocal of resistance is called –
(a) Reactance
(b) Conductance
(c) Impedance
(d) Capacitance
Answer: (b) Conductance

Q12. The work done in moving a unit positive charge around a complete circuit is –
(a) Potential difference
(b) EMF
(c) Power
(d) Resistance
Answer: (b) EMF

Q13. A device used to store electric charge is –
(a) Capacitor
(b) Ammeter
(c) Galvanometer
(d) Transformer
Answer: (a) Capacitor

Q14. The dimensional formula of force is –
(a) [MLT⁻²]
(b) [ML²T⁻²]
(c) [MLT⁻¹]
(d) [M⁰LT⁻²]
Answer: (a) [MLT⁻²]

Q15. Coulomb’s Law is related to –
(a) Gravitational Force
(b) Electrostatic Force
(c) Magnetic Force
(d) Nuclear Force
Answer: (b) Electrostatic Force

Q16. The SI unit of magnetic field is –
(a) Tesla
(b) Weber
(c) Ampere
(d) Henry
Answer: (a) Tesla

Q17. Which law explains the phenomenon of electromagnetic induction?
(a) Ohm’s Law
(b) Lenz’s Law
(c) Ampere’s Law
(d) Faraday’s Law
Answer: (d) Faraday’s Law

Q18. Which of the following is a scalar quantity?
(a) Momentum
(b) Force
(c) Energy
(d) Velocity
Answer: (c) Energy

Q19. SI unit of charge is –
(a) Coulomb
(b) Ampere
(c) Joule
(d) Volt
Answer: (a) Coulomb

Q20. Lens formula is –
(a) 1/f = 1/v + 1/u
(b) 1/f = v – u
(c) f = uv
(d) f = v + u
Answer: (a) 1/f = 1/v + 1/u

Q21. The energy of photon is given by –
(a) mc²
(b) hv
(c) ½ mv²
(d) qV
Answer: (b) hv

Q22. Kirchhoff’s first law is based on conservation of –
(a) Energy
(b) Mass
(c) Charge
(d) Momentum
Answer: (c) Charge

Q23. The refractive index of air is nearly –
(a) 1.33
(b) 1.5
(c) 1
(d) 2
Answer: (c) 1

Q24. The device used to measure current is –
(a) Voltmeter
(b) Ammeter
(c) Hygrometer
(d) Thermometer
Answer: (b) Ammeter

Q25. The unit of frequency is –
(a) Hertz
(b) Newton
(c) Joule
(d) Watt
Answer: (a) Hertz

Q26. Transformer works on the principle of –
(a) Mutual Induction
(b) Electrolysis
(c) Ohm’s Law
(d) Coulomb’s Law
Answer: (a) Mutual Induction

Q27. The property of a body to resist change in motion is –
(a) Work
(b) Energy
(c) Inertia
(d) Force
Answer: (c) Inertia

Q28. The unit of capacitance is –
(a) Henry
(b) Tesla
(c) Farad
(d) Weber
Answer: (c) Farad

Q29. The nucleus of hydrogen atom contains –
(a) 1 electron
(b) 1 proton
(c) 1 neutron
(d) 1 proton and 1 neutron
Answer: (b) 1 proton

Q30. The charge of electron is –
(a) +1.6 × 10⁻¹⁹ C
(b) –1.6 × 10⁻¹⁹ C
(c) +3 × 10⁸ C
(d) 0
Answer: (b) –1.6 × 10⁻¹⁹ C

Q31. The SI unit of work is –
(a) Joule
(b) Watt
(c) Newton
(d) Pascal
Answer: (a) Joule

Q32. The magnetic flux is measured in –
(a) Tesla
(b) Weber
(c) Ampere
(d) Henry
Answer: (b) Weber

Q33. The focal length of a plane mirror is –
(a) Infinity
(b) Zero
(c) 10 cm
(d) 20 cm
Answer: (a) Infinity

Q34. The motion of planets around the sun is –
(a) Rectilinear
(b) Circular
(c) Elliptical
(d) Random
Answer: (c) Elliptical

Q35. The splitting of white light into seven colours is called –
(a) Diffraction
(b) Dispersion
(c) Reflection
(d) Refraction
Answer: (b) Dispersion

Section B: Short Answer Type Questions (5 × 7 = 35 Marks)

Q1. State and explain 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 temperature remains constant. Mathematically, V = IR. Here, V = potential difference, I = current, R = resistance.

Q2. What is Coulomb’s Law of electrostatics?
Answer: Coulomb’s law states that the electrostatic force of attraction or repulsion between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance between them.
Formula: F = k (q₁q₂) / r²

Q3. Define Magnetic Flux and give its SI unit.
Answer: Magnetic flux is the total number of magnetic field lines passing through a given surface area.
Formula: Φ = B × A × cos θ
SI unit: Weber (Wb).

Q4. What is the difference between AC and DC current?
Answer:

AC (Alternating Current): Current changes direction periodically. Example: household electricity.
DC (Direct Current): Current flows in only one direction. Example: battery.

Q5. Write any two differences between conductor, insulator, and semiconductor.
Answer:

Conductor: Allows electricity to flow easily (e.g., copper).
Insulator: Does not allow electricity to flow (e.g., rubber).
Semiconductor: Conductivity lies between conductor and insulator (e.g., silicon).

Q6. State Kirchhoff’s Second Law.
Answer: Kirchhoff’s Second Law (Loop Law) states that in any closed loop of an electrical circuit, the algebraic sum of the EMFs is equal to the sum of the potential drops.

Q7. Write the expression for kinetic energy of an electron accelerated through a potential difference V.
Answer:
Kinetic Energy = eV
where e = charge of electron, V = potential difference.

Section C: Long Answer Type Questions (5 × 2 = 10 Marks)

Q1. Derive the expression for the focal length of a convex lens using lens formula.
Answer:
Lens formula is 1/f = 1/v – 1/u,
where f = focal length, v = image distance, u = object distance.

Using sign convention, the relation is derived based on refraction at spherical surfaces.
The derivation shows how rays of light passing through a convex lens converge to a focal point.
Diagram: A convex lens with object on left side, rays refracted and meeting at focus on right.

Q2. Explain the principle, construction, and working of a transformer.
Answer:

Principle: Transformer works on the principle of mutual induction.
Construction: It consists of a primary coil, secondary coil, and a soft iron core.
Working: When alternating current flows through the primary coil, it produces a changing magnetic flux in the core, inducing an EMF in the secondary coil.
Used for stepping up or stepping down voltage.
Diagram: Soft iron core with primary and secondary windings.

FAQs

Q1. Is this model paper based on Bihar Board 2025 exam pattern?
Yes, it is prepared according to BSEB 2025 pattern with Objective, Short, and Long answer types.

Q2. Are diagrams necessary in long answers?
Yes, neat and labelled diagrams fetch extra marks.

Q3. How many marks are allotted for objective questions?
35 marks (1 mark × 35 questions).

Q4. How can I score good marks in Physics board exam?
Focus on NCERT concepts, practice numerical problems, and revise important derivations with diagrams.

Conclusion

This Bihar Board Class 12 Physics Model Paper 2025 is designed to give students a complete idea of the exam pattern. It covers 35 objective questions, 7 short answers, and 2 long answers with solutions, strictly based on the BSEB exam scheme. Solving such model papers will help students boost confidence and score high in the final exam.

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