CBSE Class 12 Physics Pre-Board Sample Papers 2026 with Solution, Download PDF

Getting ready for your CBSE Class 12 Physics board exam might seem hard, but it's easier with the right help. That's why we made these practice papers for your Pre-Board exams in 2025-2026. They come with answers showing you how to solve the problems step-by-step. Think of these papers as a practice test before the real one. Experts made them to match the newest school book and the actual exam layout. This way, you practice exactly what you need to do well.

These practice papers are very useful. They help you see what kind of questions are asked, learn how to finish the exam on time, and find what you need to study more. When you work through these papers, you'll feel more sure of yourself and get a real idea of what the board exam will be like. The best part is you can get all these papers for free as PDF files. Everyone can get ready for the exam easily. Start practicing now to do better and get an 'A' in your Class 12 Physics exam!

CBSE Class 12 Physics: Chapter-Wise Exam Pattern & Marking Scheme

That table outlines the CBSE 12th Physics exam pattern:

CBSE Class 12 Physics Exam Pattern 2026: Unit-wise Marks distribution

The theory portion of CBSE Class 12 Physics is worth a total of 70 marks. The practicals account for the final thirty points. The chapter-by-chapter exam format and grading system for CBSE Class 12 Physics are described below:

CBSE Class 12 Physics Pre Board Sample Paper 2025-26

Section-A

1. A long straight wire of circular cross section of radius ҅a᾿ carries a steady current I. The current is uniformly distributed across its cross section. The ratio of magnitudes of the magnetic field at a point a/2 above the surface of wire to that of a point a/2 below its surface is

(A) 4:1 (B) 1:1 (C) 4: 3 (D) 3 :4

2. The diffraction effect can be observed in

(A) sound waves only (B) light waves only
(C) ultrasonic waves only (D) sound waves as well as light waves

3. In a series LCR circuit, the voltage across the resistance, capacitance and inductance is 10 V each. If the capacitance is short circuited the voltage across the inductance will be

(A) 10 V (B) 10√2 V (C) 10/√2 V (D) 20 V

4.  A uniform electric field pointing in positive X-direction exists in a region. Let A be the origin, B be the point on the X-axis at x = +1 cm and C be the point on the Y-axis at y = +1 cm. Then the potential at points A, B and C satisfy.

(A) VA < VB (B) VA > VB. (C) VA < VC (D) VA > VC

5. 

6.  A capacitor consists of two parallel plates, with an area of cross-section of 0.001 m2 , separated by a distance of 0.0001 m. If the voltage across the plates varies at the rate of 108 V/s, then the value of displacement current through the capacitor is

7. 

(A) 1-P, 2-R, 3-S, 4-Q      (B) 1-S, 2-P, 3-O, 4-R
(C) 1-Q, 2-P, 3-S, 4-R      (D) 1-S. 2-R, 3-P, 4-Q

8. Colours observed on a CD (Compact Disk) is due to

(A) Reflection (B) Diffraction (C) Dispersion (D) Absorption

9. The number of electrons made available for conduction by dopant atoms depends strongly upon

(A)doping level       (B) increase in ambient temperature
(C)energy gap       (D) options (A) and (B) both

10. The distance of closest approach of an alpha particle is d when it moves with a speed V towards a nucleus.

Another alpha particle is projected with higher energy such that the new distance of the closest approach is d/2. What is the speed of projection of the alpha particle in this case?

(A) V /2      (B) √2 V          (C) 2 V        (D) 4 V

11. A point object is placed at the centre of a glass sphere of radius 6 cm and refractive index 1.5. The distance of virtual image from the surface of the sphere is

(A) 2 cm    (B) 4 cm    (C) 6 cm    (D) 12 cm

12. If copper wire is stretched to make its radius decrease by 0.1%, then the percentage change in its resistance is approximately

(A)–0.4% (B) +0.8% (C) +0.4% (D) +0.2%

For Questions 13 to 16, two statements are given –one labelled Assertion (A) and other labelled Reason (R). Select the correct answer to these questions from the options as given below.

A. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.
B. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
C. If Assertion is true but Reason is false.
D. If both Assertion and Reason are false.

13. Assertion (A): Nuclei having mass number about 60 are least stable..

Reason (R): When two or more light nuclei are combined into a heavier nucleus then the binding energy per nucleon will decrease.

14. Assertion (A): On increasing the current sensitivity of a galvanometer by increasing the number of turns may not necessarily increase its voltage sensitivity.

Reason(R) : The resistance of the coil of the galvanometer increases on increasing the number of turns.

15. Assertion (A): In a hydrogen atom there is only one electron but its emission spectrum shows many lines.

Reason (R): In a given sample of hydrogen there are many atoms each containing one electron; hence many electrons in different atoms may be in different orbits so many transitions from higher to lower orbits are possible.

16. Assertion (A): de Broglie's wavelength of a freely falling body keeps decreasing with time.

Reason (R): The momentum of the freely falling body increases with time.

Section-B

17. (I) A beam of light consisting of two wavelengths, 4000 Å and 6000 Å, is used to obtain interference fringes in a Young’s double-slit experiment. What is the least distance from the central maximum where the dark fringe is obtained?

OR

(II) In Young’s double-slit experiment using monochromatic light of wavelength λ, the intensities of two sources are I. What is the intensity of light at a point where path difference between wavefronts is λ/4?

18.  P and Q are two identical charged particles each of mass 4 × 10–26 kg and charge 4.8 × 10–19 C, each moving with the same speed of 2.4 × 105 m/s as shown in the figure. The two particles are equidistant (0.5 m) from the vertical Y -axis. At some instant, a magnetic field B is switched on so that the two particles undergo head-on collision.

Find –
(I) the direction of the magnetic field and
(II) the magnitude of the magnetic field applied in the region.

(for VI candidates)

A proton is moving with speed of 2 x 105 m s–1 enters a uniform magnetic field B = 1.5 T. At the entry velocity vector makes an angle of 30° to the direction of the magnetic field. Calculate (a) the pitch of helical path described by the charge (b) Kinetic energy after completing half of the circle.

19. A cylindrical conductor of length l and cross-section area A is connected to a DC source. Under the influence of electric field set up due to source, the free electrons begin to drift in the opposite direction of the electric field.

 (I) Draw the curve showing the dependency of drift velocity on relaxation time.

 (II) If the DC source is replaced by a source whose current changes its magnitude with time such that I = Io sin 2πνt , where ν is the frequency of variation of current, then determine the average drift velocity of the free electrons over one complete cycle.

20. A platinum surface having work function 5.63 eV is illuminated by a monochromatic source of 1.6 x 10 15 Hz. What will be the minimum wavelength associated with the ejected electron.

21. Binding energy per nucleon vs mass number curve for nuclei is shown in the figure. W, X, Y and Z are four nuclei indicated on the curve. Identify which of the following nuclei is most likely to undergo

 (i) Nuclear Fission

 (ii) Nuclear Fusion.

 Justify your answer

Section- C

22. Find the expression for the capacitance of a parallel plate capacitor of plate area A and plate separation d when (I) a dielectric slab of thickness t and (II) a metallic slab of thickness t, where (t < d) are introduced one by one between the plates of the capacitor. In which case would the capacitance be more and why?

23. (I) Draw the energy band diagram for P-type semiconductor at

(i) T=0K and

(ii) room temperature.

(II) In the given diagram considering an ideal diode, in which condition will the bulb glow (a) when the switch is open (b) when the switch is closed Justify your ans

24. (I) Draw a ray diagram for the formation of image by a Cassegrain telescope.

(II)Why these types of telescopes are preferred over refracting type telescopes. (Write 2 points)

25. (I) Identify the circuit elements X and Y as shown in the given block diagram and draw the output waveforms of X and Y

(II) If the centre tapping is shifted towards Diode D1 as shown in the diagram, draw the output waveform of the given circuit.

26.  (I) State Gauss᾿s theorem in electrostatics. Using this theorem, derive an expression for the electric field due to an infinitely long straight wire of linear charge density .

OR

(II) (a) Define electric flux and write its SI unit.

(b) Use Gauss᾿s law to obtain the expression for the electric field due to a uniformly charged infinite plane sheet of charge. 

27.  A light ray entering a right-angled prism undergoes refraction at the face AC as shown in Fig. 1.

(I) What is the refractive index of the material of the prism in Fig. 1?

(II) (a) If the side AC of the above prism is now surrounded by a liquid of refractive index 2 , 3 as shown in Fig. 2, determine if the light ray continues to graze along the interface AC or undergoes total internal reflection or undergoes refraction into the liquid.

28. A boy is holding a smooth, hollow and non-conducting pipe vertically with charged spherical ball of mass 10 g carrying a charge of +10 mC inside it which is free to move along the axis of the pipe. The boy is moving the pipe from East to West direction in the presence of magnetic field of 2T. With what minimum velocity, should the boy move the pipe such that the ball does not move along the axis. Also determine the direction of the magnetic field.

Section - D

29. Case Study Based Question: Photoelectric effect

It is the phenomenon of emission of electrons from a metallic surface when light of a suitable frequency is incident on it. The emitted electrons are called photoelectrons. Nearly all metals exhibit this effect with ultraviolet light but alkali metals like lithium, sodium, potassium, cesium etc. show this effect even with visible light. It is an instantaneous process i.e. photoelectrons are emitted as soon as the light is incident on the metal surface. The number of photoelectrons emitted per second is directly proportional to the intensity of the incident radiation. The maximum kinetic energy of the photoelectrons emitted from a given metal surface is independent of the intensity of the incident light and depends only on the frequency of the incident light. For a given metal surface there is a certain minimum value of the frequency of the incident light below which emission of photoelectrons does not occur.

(I) In a photoelectric experiment plate current is plotted against anode potential.

(A) A and B will have same intensities while B and C will have different frequencies
(B) B and C will have different intensities while A and B will have different frequencies
(C) A and B will have different intensities while B and C will have equal frequencies
(D) B and C will have equal intensities while A and B will have same frequencies.

(II) Photoelectrons are emitted when a zinc plate is

(A)Heated (B) hammered
(C) Irradiated by ultraviolet light (D) subjected to a high pressure

(III) The threshold frequency for photoelectric effect on sodium corresponds to a wavelength of 500 nm. Its work function is about

(A) 4x10−19 J (B) 1 J (C) 2x10−19 J (D) 3x10−19 J

(IV) The maximum kinetic energy of photoelectrons emitted from a surface when photons of energy 6 eV fall on it is 4 eV. The stopping potential is

(A) 2 V (B) 4 V (C) 6 V (D) 10 V

OR

The minimum energy required to remove an electron from a substance is called its

(A) work function (B) kinetic energy (C) stopping potential (D) potential energy

30. Case Study Based Question: Motion of Charge in Magnetic Field

An electron with speed vo << c moves in a circle of radius ro in a uniform magnetic field. This electron is able to traverse a circular path as the magnetic force acting on the electron is perpendicular to both vo and B ,as shown in the figure. This force continuously deflects the particle sideways without changing its speed and the particle will move along a circle perpendicular to the field. The time required for one revolution of the electron is To

(i) If the speed of the electron is now doubled to 2vo. The radius of the circle will change to

(A) 4ro (B) 2 ro (C) ro (D) ro/2

(ii) If v = 2vo, then the time required for one revolution of the electron (To ) will change to

(A) 4 To (B) 2 To (C) To (D) To/2

(iii) A charged particle is projected in a magnetic field B = (2 i + 4 j) X 102 T . The acceleration of the particle is found to be a = ( x i + 2 j ) m/s2. Find the value of x.

(A) 4 ms-2

(B) -4 ms-2

(C) -2 ms-2

(D) 2 ms-2

(iv) If the given electron has a velocity not perpendicular to B, then trajectory of the electron is

(A) straight line (B) circular (C) helical (D) zig-zag

 OR

If this electron of charge (e) is moving parallel to uniform magnetic field with constant velocity v, the force acting on the electron is

(A) Bev (B) Be/v (C) B/ev (D) Zero

Section-E

31.  (I) Explain briefly, with the help of a labelled diagram, the basic principle of the working of an a.c. generator. In an a.c. generator, coil of N turns and area A is rotated at an angular velocity ω in a uniform magnetic field B. Derive an expression for the instantaneous value of the emf induced in coil. What is the source of energy generation in this device?

OR

(II) a) With the help of a diagram, explain the principle of a device which changes a low ac voltage into a high voltage . Deduce the expression for the ratio of secondary voltage to the primary voltage in terms of the ratio of the number of turns of primary and secondary winding. For an ideal transformer, obtain the ratio of primary and secondary currents in terms of the ratio of the voltages in the secondary and primary coils.

b) Write any two sources of the energy losses which occur in actual transformers.

c) A step-up transformer converts a low input voltage into a high output voltage. Does it violate law of conservation of energy? Explain.

32. (I) a) A giant refracting telescope at an observatory has an objective lens of focal length 15 m. If an eyepiece of focal length 1.0 cm is used, what is angular magnification of the telescope in normal adjustment?

b) If this telescope is used to view the moon, what is the diameter of the image of the moon formed by the objective lens? The diameter of the moon is 3.48 × 106 m, and the radius of lunar orbit is 3.8 × 108 m.

OR

(II) A compound microscope consists of an objective lens of focal length 2.0 cm and an eyepiece of focal length 6.25 cm separated by a distance of 15 cm. How far from the objective should an object be placed in order to obtain the final image at

a) the least distance of distinct vision (25 cm) and

b) infinity? What is the magnifying power of the microscope in each case?

33. (I) a) Write two limitations of ohm’s law. Plot their I-V characteristics.

b) A heating element connected across a battery of 100 V having an internal resistance of 1 Ω draws an initial current of 10 A at room temperature 20.0 °C which settles after a few seconds to a steady value. What is the power consumed by battery itself after the steady temperature of 320.0 °C is attained? Temperature coefficient of resistance averaged over the temperature range involved is 3.70 × 10–4 °C–1.

OR

(II) a) Using Kirchhoff'᾿s laws obtain the equation of the balanced state in Wheatstone bridge.

b) A wire of uniform cross-section and resistance of 12 ohm is bent in the shape of circle as shown in the figure. A resistance of 10 ohms is connected to diametrically opposite ends C and D. A battery of emf 8V is connected between A and B. Determine the current flowing through arm AD.

CBSE Class 12 Physics Pre Board Sample Paper 2026 Solutions

Section- A

1.

2. Sound waves as well as light waves

3. When all the given components are connected

4.

5.

6.

7. 1-S, 2-P, 3-O, 4-R

8. Diffraction

9. doping level

10. The distance of closest approach

11. (C) 6 cm

12. (C)+0.4%

13. If both Assertion and Reason are false.

14. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

15. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

16. If both Assertion and Reason are true and Reason is the correct explanation of Assertion.

Section-B

17.

18. (I)The direction of the magnetic field is perpendicular and inward into the plane of thepaper 0.5M (II) For a head-on collision to take place, the radius of the path of each ion should be equal to 0.5 m.

19.

20.

21. (i) Nuclear fission –W 0.5M Reason: As W has binding energy per nucleon less then Y and X and nucleus is larger in size. 0.5M Output waveform (across R) (ii) Due to D 1 Due to D21 Due to D Due to D2 t 1 (ii) Nuclear fusion-Z 0.5M Reason: As Z has binding energy per nucleon more then Y and X and nucleus is smaller in size.

Section-C

22.

23.  (ii) Answer will be (a) when switch is open as when switch is closed diode will be forward biased and current will by-pass the bulb

24.  (ii) • It has mirror objective, which is free from chromatic and spherical aberrations. • It can gather more light as objectives can be made larger, hence images can be brighter. Any other two equivalent examples can be accepted.

25. (I) X = Full wave rectifier2 Y = Filter2

26.  Application of Gauss’s theorem To find electric field due to a line charge let us consider an infinitely long line charge placed along XX’ axis with linear charge density λ. Our aim is to find electric field intensity at a point P distantr from the line charge. We draw a cylindrical surface of radius r and length l coaxial with the line charge. The net flux through the cylindrical gaussian surface i.e. (II) (a) Definition of electric flux and its SI unit (b)Electric field due to an infinite plane sheet of charge. Let us consider an infinite thin plane sheet of positive charge having a uniform surface charge density . Let P be the point where electric field E is to be found. Let us imagine a cylindrical gaussian surface of length 2r and containing P as shown. The net flux through the cylindrical gaussian surface.

27. (I)Since the light ray enters perpendicular to the face AB, the angle of incidence onface AC will be45° . 0.5M So,

28.

Section-D

29. I(D) II(C) III (A) IV(B) 0R IV (A)

30. I(B) II(C) III(B) IV (C) 0R IV (D)

Section-E

31.  (I) AC Generator It is a device used to convert mechanical energy into electrical energy Principle: It is based on the principle of electromagnetic induction. When a closed coil is rotated rapidly in a strong magnetic field, the magnetic flux linked with the coil changes continuously. Hence an emf is induced in the coil and a current flows in it. In fact, the mechanical energy expended in rotating the coil appears as electrical energy in the coil. Construction: Main Parts  1. Armature: It is a rectangular coil ABCD having a large number of turns of insulated copper wire wound on a soft-iron core. The use of soft-iron core increases the magnetic flux linked with the armature. 2. Field Magnet: It a strong electromagnet having concave pole pieces N and S. The armature is rotated between these pole pieces about an axis perpendicular to the magnetic field. 3. Slip Rings: The leads from the armature coil ABCD are connected to two copper rings R1 and R2 called the ‘slip rings’. These rings are concentric with the axis of the armature coil and rotate with it. 4. Brushes:These are two carbon pieces B1 and B2 called brushes which remain stationary pressing against the slip rings R1 and R2 respectively. The brushes are connected to an external circuit. Working Theory : When the coil ABCD is rotated inside the field, an emf is induced between its two ends. Let the plane of the coil be at right angles to the magnetic field at t = 0 and angular speed of the rotation of the coil be ω. Then at time t, θ = ωt. The magnetic flux linked with the coil at time t is (II) (a)TRANSFORMER Use: It is a device which converts low ac voltage at high current into high ac voltage at low current and vice – versa. Principle: It consists of two coils P and S wound on a closed soft iron core. The coil which is fed from the ac supply is called primary coil (P) and the other connected to the load is called secondary coil (S). The core of the transformer is made of soft -iron toreduce hysteresis loss and is laminated to reduce eddy current losses. Working: When an alternating emf ep is impressed on the primary winding it sends an ac current through it which sets up an alternating magnetic flux in the core. This induces an alternating emf es in the secondary. If NP and Ns are the number of turns in primary and secondary coil, their linkages with the flux are

32.

33. (I) (a) Kirchhoff’s I Law :The algebraic sum of all the currents meeting at a point in an electrical circuit is always equal to zero. Kirchhoff’s II Law :The algebraic sum of the changes in potential around any closed resistor loop must be zero.

Also Check:

• CBSE Class 12th Syllabus 2025-26 (All Subjects)
• NCERT Books for CBSE Class 12 - Latest Edition
• NCERT Solutions for CBSE Class 12 - Updated