MBOSE Class 12 Question Paper 2026 for Physics

FOR MBOSE CLASS 12 EXAM PREPARATION

MBOSE Class 12 2026
Question Paper ·
Physics
EXAM YEAR TYPE SUBJECT

MBOSE Class 12 2026 Question Paper Physics

Notes · Sample Papers · Previous Year Papers · Mock Tests

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Total No. of Printed Pages—12
HS/XII/Sc/Ph/26
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s e m
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g l a PHYSICS
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a ( Theory )

Full Marks : 70

Time : 3 hours

The figures in the margin indicate full marks for the questions

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General Instructions :

1. There are 33 questions
e mAll questions are
in all.
compulsory.
l as
ag Sections : Section—A
2. This Question Paper has five
Section—B, Section—C Section—D and Section—E.
3. All the Sections are compulsory.
4. Section—A contains sixteen questions—twelve multiple
choice type questions and four very short answer type
questions of 1 mark each. Section—B contains five
questions of 2 marks each, Section—C contains seven
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questions of 3 marks each, Section—D contains two case
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study-based questions of 4 marks each and Section—E
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contains three long answer type questions of 5 marks
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ag 5. There is no overall choice. However internal choices
have been provided in two questions in Section—A, two
questions in Section—B, three questions in Section—C
and all three questions in Section—E. You have to
attempt only one of the choices in such questions.

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( 2 )

6. You may use the following values of physical constants
where necessary :
c = 3 ´ 10 8 m/s

m e = 9 × 1 ´ 10 -31 kg

m p = 1 × 7 ´ 10 -27 kg

e = -1 × 6 ´ 10 -19 C

m 0 = 4p ´ 10 -7 T m A -1

h = 6 × 63 ´ 10 -34 J-s

e 0 = 8 × 854 ´ 10 -12 C2 N -1 m -2

Avogadro’s number = 6 × 023 ´ 1023 per gram mole

SECTION—A

Choose and write the correct option for the following : 1×12=12

1. A hollow metal sphere of radius R is uniformly charged.
The electric field due to the sphere at a distance r from the
centre

(a) increases as r increases for r < R and for r > R

(b) is zero as r increases for r < R and decreases as r
increases for r > R

(c) is zero as r increases for r < R and increases as r
increases for r > R

(d) decreases as r increases for r < R and for r > R

HS/XII/Sc/Ph/26/69 [ Contd.

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2. The time taken by an AC of frequency 50 Hz to reach from
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zero to the maximum value is
(a) 50 ´ 10 - 3 m s e
s e s
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(b) 5 ´ 10l a
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(c) 1 a
´ 10 - 3
s
(d) 2 ´ 10 - 3 s

3. The flux on a coil of 50 turns changes from 0·3 Wb to
0·5 Wb in 8 seconds. The induced e.m.f. in the coil is
(a) 10 V
(b) 0·6 V
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(c) – 12 V
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(d) – 1·25 V
s em
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a
4. Which of the following is not true
(a) It is used in TV remotes
(b) It is used in fighter aircrafts to see at night
(c) It is used for relieving muscle pulls
(d) It is used to detect cracks in metals

5. The diagram
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a (a) concave lens
(b) convex lens
(c) plane sheet of glass since it is of equal thickness
(d) convexo-concave lens

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( 4 )

6. Select the correct option with respect to the figures given
below :

I I

-2l -l 0 l 2l -4l -2l -l 0 l 2l 4l

Fig. (i) Fig. (ii)

(a) Fig. (i) depicts diffraction pattern and Fig. (ii) depicts
interference pattern

(b) Both depict interference pattern

(c) Both depict diffraction pattern

(d) Fig. (i) depicts an interference pattern due to a
double-slit and Fig. (ii) depicts a diffraction pattern
due to a single-slit

7. The electron in a hydrogen atom makes a transition from
an excited state to the ground state. Which of the
following statements is true?

(a) Its kinetic energy increases and its potential and total
energies decrease.

(b) Its kinetic energy decreases, potential energy
increases and its total energy remains the same.

(c) Its kinetic and total energies decrease and its
potential energy increases.

(d) Its kinetic energy, potential energy and total energy
all decrease.

HS/XII/Sc/Ph/26/69 [ Contd.

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8. If a charged particle enters perpendicularly into a uniform
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magnetic field, then which of the following statements is
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true?
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(a) Both

(b) Energy remains constant, but momentum changes.

(c) Both energy and momentum change.

(d) Energy changes but momentum remains constant.

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. needle is placed
9. In the figure shown below, a compass m
e in the South-North
s
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under the wire. The wire is aligned
g
wire from S to N, the needleawill
direction. When a current is made

N

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m (a) deflect to the right s e m
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a (b) deflect to the left

(c) turn 180º

(d) remain unaffected

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( 6 )

10. The figure given below shows the phase relationship
between voltage E and current I . Which of the following
statements is true?

E
I

0 p p 3p 2p 5p wt
2 2 2

(a) This phase relationship is for a resistor when AC is
passed through it.

(b) This phase relationship is for a capacitor when AC is
passed through it.

(c) This phase relationship is for an inductor when AC is
passed through it.

(d) This phase relationship is for an L-C-R circuit.

11. Which of the following statements is true regarding the
stability of a nucleus?

(a) Binding energy alone determines nuclear stability.

(b) Binding energy per nucleon is a better indicator of
nuclear stability than total binding energy.

(c) Neither binding energy nor binding energy per
nucleon is related to nuclear stability.

(d) Only the number of protons and neutrons determine
nuclear stability.

HS/XII/Sc/Ph/26/69 [ Contd.

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12. Two long straight wires are set parallel to each other.
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Each carries the same current in the same direction and
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the separation between them is 2r. The intensity of the
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magnetic field midway between them is

0Ig
(a) ma
l
r
(b) 4m 0I
r
(c) zero
(d) m 0I
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4r

Answer the following questions :
e m 1×4=4

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a g in the first orbit of
13. If the binding energy of an electron
hydrogen atom is -13 × 6 eV, then what is the binding
energy in the orbit n = 3?

Or

A hydrogen atom initially in the ground level absorbs a
photon which excites it to the n = 4 level. Determine the

m
frequency of the photon.

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14. What is the fringe width in Young’s double-slit experiment
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s e if a monochromatic ray of wavelength 5 ´ 10 - 5 cm falls on
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a
a screen is held at a distance of 5 cm?

15. If the angle of minimum deviation of an equilateral prism
is 39·5º, find the refractive index of the material of the
prism.

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( 8 )

16. A parallel-plate capacitor of plate area 2 m2 , separated by
a distance of 1 mm is immersed in castor oil of dielectric
constant 4·7. What is its capacitance?

Or

Two capacitors each charged with 4 × 8 ´ 10 - 8 C are
connected in parallel to each other. If the potential
difference of one of the capacitors is 12 V, calculate the
total energy stored in both the capacitors.

SECTION—B

17. Name the electromagnetic waves used for (a) treating
cancer and (b) night vision. 2

18. On connecting two resistances of 24 W and 8 W in parallel
across a 12 V battery, a current of 1·5 A is seen to flow.
What is the internal resistance of the cell? 2

19. Derive an expression for the torque acting on an electric
dipole when placed in a uniform electric field. 2

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20. Derive the expression B = for the magnetic field due
2 pr
to a straight conductor, using Ampere’s circuital theorem. 2

Or

What is the magnetic field at the centre of a current-
carrying circular coil? Derive the expression.

HS/XII/Sc/Ph/26/69 [ Contd.

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21. Draw the binding energy per nucleon curve and in it,
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mark the positions of 1H2 and Fe. 1+½+½=2
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Or

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l and a proton are accelerated through the
same a potential difference. Find the ratios of their
An a-particle

velocities. 2

SECTION—C

22. With the help of a diagram, explain the working of
full-wave rectifier, using a p-n junction diode. 1+½+½+1=3
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Draw the forward characteristic curve of a p-n junction

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diode. Explain the terms depletion region and barrier
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potential or junction potential.
a 1+1+1=3

23. Considering the drift of electrons through a conductor
under a potential difference, derive the expression
I = neAv d , where the symbols have their usual meanings. 3
Or
Derive Ohm’s law from the expressions of drift velocity
and current.
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24. Derive an expression for the velocity of an electron in the
s e3m
s e nth orbit of a hydrogen atom according to Bohr.
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a (a) State the postulates of Bohr’s theory of hydrogen
atom. 2
(b) Name the series of hydrogen spectrum lying in
ultraviolet and visible region. ½+½=1

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( 10 )

25. Derive Lens Maker’s formula, assuming the results for
refraction from rarer to denser and denser to rarer across
a convex surface. 3

26. With the help of a proper ray diagram, obtain an
expression for the magnification produced by a simple
microscope. 3

27. Using Biot-Savart law, find the expression for magnetic
field at any point on the axis of a circular coil carrying
current. 3

I
28. Show that I RMS = 0 for an alternating current.
2 3

SECTION—D

29. Doping is a process of adding impurities of either of two
specific types to a pure semiconductor. This is done
specifically to produce a doped semiconductor having
tailor-made properties to satisfy specific needs. The
addition of an impurity having valency three produces
p-type semiconductor and the addition of an impurity
having valency five produces n-type semiconductor.
(a) What would happen if instead of trivalent or
pentavalent impurities, bivalent or hexavalent
impurities respectively were added to obtain p-type or
n-type semiconductors? Explain. 2
(b) In n-type semiconductors electrons are majority
charge carriers. Is an n-type semiconductor
negatively charged? Explain. 2

HS/XII/Sc/Ph/26/69 [ Contd.

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( 11 )

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30. In an experiment with two different photosensitive metals,
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the plot of photo-current (I ) versus collector plate potential
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(V ) was obtained as shown in the figure below. The
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frequency and intensity of incident light was constant :
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Metal B
Metal A

-V2 -V1 0 V

(a) What conclusion can be drawn about the work

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functions of metals A and B from the graph? Explain. 2

co A change if
(b) How would the stopping potential of .metal
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s be affected if the
the intensity of incident light were 1

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(c) How would stopping potential
frequency of incident light 1

SECTION—E
31. What are polar and non-polar dielectrics?
Find an expression for the capacity of a parallel-plate
capacitor with plate separation d, in which a dielectric of
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dielectric constant K is inserted having thickness t < d .
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2+3=5
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Or

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done in moving a charge from one point to another
an equipotential surface is zero.
(b) Using Gauss’ law, derive an expression for the electric
field intensity at a point due to an infinitely long
straight uniformly charged wire. 2+3=5

HS/XII/Sc/Ph/26/69 [ P.T.O.

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( 12 )

32. In Young’s double-slit experiment, obtain the conditions
for constructive and destructive interference. 2½+2½=5

Or

With the help of a proper ray diagram, obtain the
expression for magnification produced by a compound
microscope when final image is formed at least distance of
distinct vision. 2+3=5

33. (a) With the use of a phasor diagram, derive an
expression for the impedance of a series L-C-R circuit.
(b) What is power factor of an AC circuit? Write its
mathematical expression. 5

Or

(a) With the help of a schematic diagram, explain the
theory and working of a transformer. Also show that
transformation ratio K depends on the ratio of the
number of turns in secondary to primary.
(b) What is copper loss in a transformer? 4+1=5

HHH

HS/XII/Sc/Ph/26/69 26K—5780

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