CBSE Class 12 Question Paper 2026 Physics

FOR CBSE CLASS 12 EXAM PREPARATION

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

CBSE Class 12 2026 Question Paper Physics

Notes · Sample Papers · Previous Year Papers · Mock Tests

m
m .co

m .co s e m
se g l a
Series : QPSR1 a SET~1

55/1/1
- 
Q.P. Code
 .
Roll No.  -   - 
-    
Candidates must write the Q.P. Code
m
m on the title page of the answer-book.
.co
.co s e m
s em   () l a
g la PHYSICS (Theory) ag
a : 3 
    : 70
Time allowed : 3 hours Maximum Marks : 70

 : NOTE :
(I)       -   (I) Please check that this question
 31   paper contains 31 printed pages.

(II) -        - (II)omQ.P. Code given on the right
    -  - .c hand side of the question paper
m should be written on the title
   
la se page of the answer-book by the
a g candidate.
(III)       -  33  (III) Please check that this question
  paper contains 33 questions.

(IV)         , (IV) Please write down the serial
-       number of the question in the
answer-book at the given
   place before attempting it.
(V)
 -     15   (V) 15 minute time has been allotted
m
o m      -   
c  10.15     10.15   m .co
to read this question paper. The
. question paper
s
will
e be

s em 10.30     - 
g a
distributed at 10.15 a.m. From
l
10.15 a.m. to 10.30 a.m., the
g la        - candidates a
will read the
a       {} question paper only and will not
write any answer on the answer-
book during this period.

~55/1/1~ 2383-1 1  P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 1 of 32

  :
         
(i)  -  33        
(ii)  -      – -, , ,    
(iii)  –     1  16          1    
(iv)  –     17  21   -        2 
  
(v)  –     22  28  -        3 
  
(vi)  –     29  30  -      4 
  
(vii)  –     31  33  -        5 
  
(viii) -         , -       
      
(ix)          -  
(x)      
  ,            :
c = 3  108 m/s
h = 6.63  10–34 J s
e = 1.6  10–19 C
0 = 410–7 Tm A–1
0 = 8.854 × 10–12 C2 N–1 m–2
1
= 9  109 N m2 C–2
40
   (me) = 9.1  10–31 kg
   = 1.675 × 10–27 kg
   = 1.673 × 10–27 kg
  = 6.023 × 1023   
  = 1.38 × 10–23 J K–1

~55/1/1~ { } 2  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 2 of 32

m
m .co

m .co s e m
se g l a
General Instructions :
a
Read the following instructions very carefully and follow them :
(i) This question paper contains 33 questions. All questions are
compulsory.
(ii) Question paper is divided into FIVE sections – Sections A, B, C, D
and E.
(iii) In Section A : Question numbers 1 to 16 are Multiple Choice (MCQ) type
m
questions. Each question carries 1 mark.
m .co
m .co
(iv) In Section B : Question numbers 17 to 21 are Very Short Answer (VSA)
s e m
type questions. Each question carries 2 marks.
s e l a
g l a
(v) In Section C : Question numbers 22 to 28 are Short Answer (SA) type
questions. Each question carries 3 marks. ag
a
(vi) In Section D : Question numbers 29 & 30 are Case Study-Based
questions. Each question carries 4 marks.
(vii) In Section E : Question numbers 31 to 33 are Long Answer (LA) type
questions. Each question carries 5 marks.
(viii) There is no overall choice given in the question paper. However, an internal
choice has been provided in few questions in all the Sections except
Section A.
m
.co
(ix) Kindly note that there is a separate question paper for Visually Impaired
candidates.
e m
(x) Use of calculator is NOT allowed.
las
c = 3  108 m/s ag
You may use the following values of physical constants wherever necessary :

h = 6.63  10–34 J s
e = 1.6  10–19 C
0 = 4 10–7 T m A–1
0 = 8.854 × 10–12 C2 N–1 m–2
1
= 9  109 N m2 C–2
m
.co
40
m
m .co Mass of electron (me) = 9.1  10–31 kg
s e m
s e Mass of neutron = 1.675 × 10–27 kg
g l a
g la Mass of proton = 1.673 × 10–27 kg a
a Avogadro’s number = 6.023 × 1023 per gram mole
Boltzmann’s constant = 1.38 × 10–23 J K–1

~55/1/1~ { } 3  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 3 of 32

 – 

1.       V = 10 – 50x     ,  V  
   x            1

(A) +x    10 N/C

(B) –x    10 N/C

(C) +x    50 N/C

(D) –x    50 N/C



2.      ‘A’  ‘B’     r1  r2     
       ,           ‘A’  ‘B’
       (EA/EB)  – 1

r1 r2
(A) r (B) r
2 1

2 2
r1 r2
(C) 2 (D) 2
r2 r1



3.     ,       a ,    I   
                   a/2   
            – 1

0I
(A)  (B)
2a

0I 0I
(C) (D)
4a 6a

~55/1/1~ { } 4  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 4 of 32

m
m .co

m .co s e m
se g l a
SECTION – A
a
1. In a region, the electric potential varies as V = 10 – 50x, where V is in
volts and x in meters. The electric field in the region is  1

(A) 10 N/C along +x

m
.co
(B) 10 N/C along –x
m
(C) 50 N/C along +x
m .co s e m
s e l a
ag
(D) 50 N/C along –x
g l a

a
2. A conducting wire connects two charged metallic spheres A and B of radii
r1 and r2 respectively. The distance between the spheres is very large
compared to their radii. The ratio of electric fields, (EA/EB) at the surfaces
of spheres A and B will be 1

r1 r2
m
(A) r
2
(B) r
1 .co
s em
la (D) r
2 2
r1
(C)
r2
2 ag r
2
2
1



3. A long straight wire of circular cross-section (radius a) carries a steady
current I. The current is uniformly distributed across this cross-section.
The magnitude of the magnetic field produced at a point at a distance
m
.co
(a/2) from the axis of the wire will be 1
m
c. o (A) Zero 0I
s e m
e m (B)
2a
l a
las ag
ag (C)
0I
(D)
0I
4a 6a

~55/1/1~ { } 5  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 5 of 32

4.     ,                 
  ,         – 1

(A)  (B) 

(C)  (D) 


5.                
 (3/2)    (8/3)     – 1

(A)          

(B)           

(C)         

(D)       

6.   LCR  , ,   ,       10 V
                  – 1

(A) 10 V (B) 5 2 V

5
(C) V (D) 10 2 V
2

7.                 –
    1

(A) 1 nm  10–3 nm (B) 400 nm  1 nm

(C) 1 mm  700 nm (D) 0.1 m  1 mm

~55/1/1~ { } 6  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 6 of 32

m
m .co

m .co s em
se g la
4.
a
The shape of the interference fringes in Young’s double-slit experiment,
when the distance between the slit and the screen is very large as
compared to the slit-separation, is nearly 1

(A) straight (B) parabolic

(C) circular (D) hyperbolic
m
m .co
.co


5. An electromagnetic wave passes from vacuum into a dielectric medium e m
s em electrical permittivity (3/2) and relative magnetic glas
with relative
g la (8/3). Then, its a 1
a
permeability

(A) wavelength is doubled and frequency remains unchanged.

(B) wavelength is doubled and frequency is halved.

(C) wavelength is halved and frequency remains unchanged.

(D) wavelength and frequency both will remain unchanged.
m
.co
6. s em
In a series LCR circuit, the voltage across the resistor, capacitor and

g la is short circuited, the voltage across
inductor is 10 V each. If the capacitor
the inductor will be
a 1

(A) 10 V (B) 5 2 V

5
(C) V (D) 10 2 V
2

o m
7.omElectromagnetic waves used in a diagnostic tool in medicine
c
. have a
c. e m
e m wavelength range l as 1
l as a g
ag (A) 1 nm to 10 nm –3 (B) 400 nm to 1 nm

(C) 1 mm to 700 nm (D) 0.1 m to 1 mm

~55/1/1~ { } 7  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 7 of 32

8.   -,   ,           
    ( ) ‘d’            
,       - 1

d
(A) 2 (B) 2d

d
(C) 4 (D) 4d

9. 10 cm                 
     -  – 1

(A) 20 cm (B) 30 cm
(C) 40 cm (D) 5 cm

10.  -         1

(i) y1 = A1 sin t (ii) y2 = A2 sin 2 t

(iii) y3 = A3 cos t (iv) y4 = A4 sin (t + /3)

   
(A)  (i)  (iii)   (B)  (iii)  (iv)  
(C)  (i), (iii)  (iv)   (D)     

V
11.    ,        (P1, V)  (P2, V) , 2  
 (dc)                 – 1

P 1 + P2
(A) (P1 + P2) (B) 2
P1 P 2 P1 P 2
(C) 2(P + P ) (D) 4(P + P )
1 2 1 2

~55/1/1~ { } 8  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 8 of 32

m
m .co

m .co s em
se g la
8.
a
The ‘distance of closest approach’ of an alpha-particle is ‘d’ when it moves
with a velocity  head-on towards the target nucleus. If the velocity of
alpha particle is halved, the new ‘distance of closest approach’ will be – 1
d
(A) 2 (B) 2d

d m
(C) 4
m (D) 4d
.co
m .co s e m
s e
lens of focal length 10 cm is cut into two identical plano-concave g
l a
9. a
A concave
g l a
a
lenses. The focal length of each lens will be 1
(A) 20 cm (B) 30 cm
(C) 40 cm (D) 5 cm

10. Four independent waves are expressed as 1
(i) y1 = A1 sin t
o m (ii) y2 = A2 sin 2 t
c
. y = A sin (t + /3)
(iii) y = A cos t m
(iv)
e
3 3
s
a waves is possible in
The interference between two oflthese
4 4

g
a (B) (iii) and (iv) only
(A) (i) and (iii) only
(C) (i), (iii) and (iv) only (D) All of them

11. Two heaters rated as (P1, V) and (P2, V) are connected in series across a dc
V
source of 2 volt. The power consumed by the combination will be –
m 1
m c. o
c. o (A) (P + P ) P 1 + P2
s e m
e m 1 2 (B) 2
l a
las ag
ag P1 P 2
(C) 2(P + P )
P1 P 2
(D) 4(P + P )
1 2 1 2

~55/1/1~ { } 9  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 9 of 32

12.     p-n              ? 1

(A)           
(B)           
(C)          
(D)             

 :   13  16          –      (A)  
  (R)                 (A), (B),
(C)  (D)      :

(A)  (A)   (R)      (R),  (A)     
(B)  (A)   (R)   ,   (R),  (A)      
(C)  (A)  ,   (R)   
(D)  (A)   (R)     

13.  (A) :           1

 (R) :            

14.  (A) :               
    1

 (R) :           

15.  (A) :              
  1

 (R) :               

16.  (A) :    -          1

 (R) :              
            

~55/1/1~ { } 10  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 10 of 32

m
m .co

m .co s em
se g la
a
12. In an unbiased p-n junction, at equilibrium, which of the following
statements is true ? 1
(A) Diffusion current is zero but drift current exists.
(B) Diffusion current exists but drift current is zero.
(C) Diffusion and drift currents are equal and opposite.
(D) Both the diffusion and drift currents exist but are unequal.
m
m .co
m .co
For question number 13 to 16, two statements are given – one labelled as
s e m
e
Assertion (A) and the other labelled as Reason (R). Select the correct
s l a
a
answer to these questions from the options (A), (B), (C) and (D) as given
g l ag
a
below :
(A) Both Assertion (A) and Reason (R) are true and Reason (R) is the
correct explanation of the Assertion (A).
(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the
correct explanation of the Assertion (A).
(C) Assertion (A) is true, but Reason (R) is false.

m
(D) Both Assertion (A) and Reason (R) are false.
o
13. Assertion (A) : All atoms have a netm
. c
magnetic moment. 1
s
Reason (R) : A current loop doesanot
e always behave as a magnetic dipole.
g l
a
14. Assertion (A) : If accelerated electrons are passed through a narrow slit,
a diffraction pattern is observed. 1
Reason (R) : Electrons behave as both particles and waves.

15. Reason (A) : The mass of a nucleus is less than the sum of the masses of
the constituent nucleons. 1
Reason (R) : Energy is absorbed when the nucleons are bound together to
m
m form a nucleus.
c.16.o Reason (A) : In Bohr model of hydrogen atom, the energy mlevels are .co
s e
s em discrete and quantised.
g l a 1
la a
ag Reason (R) : In a hydrogen atom, the electrostatic force on the electron
provides the necessary centripetal force to it to revolve
around the nucleus.

~55/1/1~ { } 11  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 11 of 32

 – 
17.         200 nm      
      –0.80 V             
  -     (eV)     2

18. (a)         400 nm  600 nm    
1 mm                  

1.5 m                 

           2


(b)            0.6 mm   440 nm 
660 nm          1.5 m    

                 
             

19. L       -  (i) N       (ii) N 

                  
     ,           
            -    
  -          2

20.         -   ?     
           2

21.                    
               2

~55/1/1~ { } 12  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 12 of 32

m
m .co

m .co s e m
se g l a
SECTION - B
a
17. In a photoelectric experiment, the emitter plate is irradiated with
radiation of 200 nm. The photocurrent becomes zero when the collector
plate potential is – 0.80 V. Calculate the work function (in eV) of the
emitter. 2

m
.co
18. (a) A beam of light consisting of two wavelengths 400 nm and 600 nm is
o m m
. c
used to illuminate a single slit of width 1 mm. Find the least
e
distance
e m of the point from the central maximum where the dark las
as
fringes
l due to both wavelengths coincide on the screen placed 1.5 m g
a 2
agfrom the slit.
OR
(b) In a Young’s double-slit experimental set-up with slit separation
0.6 mm a beam of light consisting of two wavelengths 440 nm and
660 nm is used to obtain interference pattern on a screen kept 1.5 m
in front of the slits. Find the least distance of the point from the
central maximum where the bright fringes due to both them
wavelengths coincide. .co
s em
19. A wire of length L is bent round
g lainto (i) a square coil having N turns and
(ii) a circular coil having Naturns. The coil in both cases is free to turn
about a vertical axis coinciding with the plane of the coil, in a uniform,
horizontal magnetic field and carry the same currents. Find the ratio of
the maximum value of the torque acting on the square coil to that on the
circular coil. 2

20. What is the order of magnitude of drift velocity of electrons in a conductor ?
m
m Deduce the relation between the current flowing through a conductor and
c. o drift velocity of electrons in it. m .co
s e 2

s em 21. Draw the plot of potential energy of a pair of nucleonsglaas a function of
g la a
a their separation. Write two important conclusions that can be drawn from
this plot. 2

~55/1/1~ { } 13  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 13 of 32

 – 

22. (a)               ,
               3

(b)  ,                 
         (i)   (ii)       
    ?



(a)    
      

(b)          A  B       

23. C                   

     V              
                
    ? 3

(a)    

(b)     

(c)       

            

~55/1/1~ { } 14  P.T.O

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m
m .co

m .co s e m
se g l a
SECTION – C
a
22. (a) Using Gauss’s law, deduce an experession for electric field at a point
due to a uniformly charged infinite plane thin sheet. 3

(b) Two large thin plane sheets, each having surface charge density 
are held close and parallel to each other in air. What is the net m
m .co
.co
electric field at a point (i) inside and (ii) outside, the sheets ?
e m
em l as
l as OR
ag
g
(a) a Obtain the condition of balance of a Wheatstone bridge.

(b) Find net resistance of the network of resistors connected between A
and B, as shown in figure.

m
m .co
s e
g la
a
23. A parallel plate capacitor of capacitance C has a dielectric slab between
its plates. It is charged to a potential difference V by connecting it across a
battery. The battery is then disconnected. If the dielectric slab is now
withdrawn from the capacitor, how will the following be affected ? 3

m
.co
(a) Capacitance of the capacitor,
m
c. o (b) Energy stored in the capacitor, and s em
e m la
las a g
(c) The potential difference between the plates of the capacitor.
ag
Justify your answer in each case.

~55/1/1~ { } 15  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 15 of 32

24.    2 cm         P1 P1'  P2 P2'     
     3  107 m/s             
    3

     3 cm     V       
    -   P2'    

25.

          A  B    (ac) 
Vi = 12 sin (100 t) V         3
  Vi   -   
(a)               ?
(b)              
(c)                  
   - V0    

26. p-n                 3

~55/1/1~ { } 16  P.T.O

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m
m .co

m .co s em
se g la
a
24. Figure shows a narrow beam of electrons entering with a velocity of
3  107 m/s, symmetrically through the space between two parallel
horizontal plates P1 P1' and P2 P2' kept 2 cm apart. 3

m
m .co
.co s e m
s em g l a
g
If eachl aplate is 3 cm long, calculate the potential difference V a
applied
a
between the plates so that the beam just strikes the end P ' . 2

25.

m
m .co
s e
g la
a
An ac voltage Vi = 12 sin (100 t)V is applied between points A and B in a
network of two ideal diodes and three resistors as shown in figure.
During the positive half-cycle of the input voltage Vi supplied to the
network. 3
(a) Identify which of the two diodes will conduct and why ?
m
m (b) Redraw an equivalent circuit diagram to show the flow of current.
c. o (c) Calculate the output voltage drops V across the three sresistors
m when .co
e
em
0

s the input voltage attains its peak value.
g l a
la a
ag 26. Briefly explain the two important processes that occur during the
formation of a p-n junction. 3

~55/1/1~ { } 17  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 17 of 32

27. (a)          -   
           
(b)              
     ? 3

28. (a)               3

(b)

        A, B  C    , 
3 2
  n, 4 n  3 n   A  B        
                    
2
 sin > 3     C     

 – 
29.           /      
                  
         -           
         ,     ,    
              -   
                
            4

~55/1/1~ { } 18  P.T.O

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m
m .co

m .co s em
se g la
a
27. (a) Draw the ray diagram to show the image formation by a refracting
telescope and write the expression for angular magnification for the
telescope in normal adjustment.
(b) Give two reasons to explain why a reflecting telescope is preferred
over a refracting telescope. 3

m
28. (a)
m
State the two conditions under which total internal reflection occurs. 3
.co
(b)
m .co s e m
s e l a
g l a ag
a

A transparent container contains layers of three immiscible
3 2
transparent liquids A, B and C of refractive indices n, 4 n and 3 n,
m
.co
respectively. A laser beam is incident at the interface between A and
m
e
B at an angle  as shown in figure. Prove that the beam does not enter
s
2 la
region C at all for sin  > g
a 3.
SECTION – D

29. A galvanometer is used to detect or/and measure small currents in an
electrical circuit. It essentially works on the fact that a current-carrying
coil experiences a deflecting torque when placed in a magnetic field. This
m
m deflection in the coil can be measured and it is related to the current
c. o flowing in the coil, the number of turns in the coil, area of the m .co
s e coil and the

s em magnetic field. A hair spring attached to the coil providesglaacounter torque
la and helps in measuring the deflection. A galvanometer a can be converted
ag to an ammeter or a voltmeter of desired range by using suitable
resistances. 4

~55/1/1~ { } 19  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 19 of 32

(I)               - 
 ,     

(A) -            

(B)   

(C)  -    

(D)       -     

(II)    -           

(A)         

(B)          

(C)            

(D)        

(III)        4.0  10–3 m2     

50    0.25 T             5A   

       -   

(A) 1.0 N m (B) 2.0 N m

(C) 0.50 N m (D) 0.25 N m



~55/1/1~ { } 20  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 20 of 32

m
m .co

m .co s em
se g la
a
(I) The torque on the coil remains constant irrespective of the coil’s
orientation during rotation due to

(A) use of soft iron core which increases the magnetic field.

(B) radial magnetic field
m
m
(C) hair spring which provides the counter torque .co
m .co s e m
e
(D) eddy current in the iron core which causes damping.
s l a
g l a ag
a
(II) The best way to increase current sensitivity of a galvanometer is by

(A) increasing number of turns of the coil

(B) increasing area of coil and magnitic field strength

m
.co
(C) decreasing area of coil and magnetic field strength
m
s e
la
(D) increasing torsional constant of the hair spring

ag
(III) A moving coil galvanometer has a coil with area of cross-section
4.0  10–3 m2 and number of turns 50. The coil is rotating in a

magnetic field of 0.25 T. The torque acting on the coil when a current
of 5 A passes through it is
m
m .co
m .co (A) 1.0 N m (B) 2.0 N m
s e m
s e l a
(D) 0.25 N m g
g la (C) 0.50 N m
a
a OR

~55/1/1~ { } 21  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 21 of 32

      15      3 mA     
     (0-12V)         
    
(A) 4015  (B) 3985 
(C) 415  (D) 385 

(IV)       20    5 mA      
     (0 – 10A)          
 -
(A) 0.05       

(B) 0.05       

(C) 0.01       

(D) 0.01       

30.     A  B           
-       A  B          
      (Vs)        A  B  
    (ν)      (Vs)       
    4

~55/1/1~ { } 22  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 22 of 32

m
m .co

m .co s em
se g la
a
A galvanometer coil has a resistance of 15  and the meter shows
full scale deflection for a current of 3 mA. The value of resistance
required to convert it into a voltmeter of range (0 – 12 V) is
(A) 4015  (B) 3985 
(C) 415  (D) 385 

m
m .co
.co
(IV) A galvanometer with coil of resistance 20  shows full scale
s e m
em
deflection for a current of 5 mA. To convert it into an ammeter of
s l a
g la
range (0 – 10 A), a resistance of
ag
a (A) 0.05  should be connected in series with it.
(B) 0.05  should be connected in parallel with it.
(C) 0.01  should be connected in parallel with it.
(D) 0.01  should be connected in series with it.

m
30. A researcher performs an experiment on photo-electric effect using two
.co
metals A and B with unknown work functions. She illuminates the
em
surfaces of A and B with monochromatic radiation of various frequencies
s
la
and records the value of corrosponding stopping potentials (Vs). The graph
g
a potential (V ) with the frequency of
shows the variation of stopping s
incident radiation (ν) for metals A and B. 4

m
m .co
m .co s e m
s e g l a
g la a
a

~55/1/1~ { } 23  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 23 of 32

     
(I)     A  B    :
(h    e      )

(A) ν1  ν2 (B) V1  V2

hν1 hν2
(C) hν1  hν2 (D) e  e

(II) A  B        ν > ν2     

 -   -
(A)  A           
(B)  B           
(C)  B              
(D) A  B              

 

(III)         A  B      

      , 
(A)       
(B)       
(C) A  B         

(D)               
  
~55/1/1~ { } 24  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 24 of 32

m
m .co

m .co s e m
se g l a
Answer the following questions :
a
(I) From the graph, the work functions of A and B are (h is Planck’s
constant and e value of charge on an electron)

(A) ν1 and ν2 (B) V1 and V2

m
m hν1 hν2
.co
.co
(C) hν1 and hν2 (D) e and e
e m
em l as
las ag
g
(II)a For radiation of frequency ν > ν incident on the surfaces of A and B,
2

the maximum kinetic energy of ejected electron is

(A) greater for metal A because it has a smaller work function.

(B) greater for metal B because it has a larger work function.

m
.co
(C) greater for metal B because it has higher threshold frequency.

em
(D) the same for both metal A and metal B because it is
s
la
independent of workgfunctions of metals.
a
(III) If the intensity of the incident radiation for both metals A and B, is
doubled keeping its frequency constant, then

(A) the slope of the parallel lines will increase.
m
m (B) the slope of the parallel lines will decrease. .co
m .co s em
s e g la
(C) the threshold frequencies for both A and B will decrease.

g la a but more electrons
(D) the slope of the parallel lines will not change
a will be emitted per second.

~55/1/1~ { } 25  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 25 of 32

(IV)        ν0    3ν0      

          E1     
 6ν0           E2    
E1
    
E2

(A) 1/3 (B) 1/2

(C) 2/5 (D) 3/4


   B   -   m    e      ,
    ‘h’     -
1
(A) me (B) me

m e
(C) e (D) m

 – 
31. (a)        q  –q 2a         

    r            E   
         r >> a       
 
(b)   x-y         q  –q  x = a  x = b 
 N 
         E = 2 ^i C         F

 -      5



~55/1/1~ { } 26  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 26 of 32

m
m .co

m .co s em
se g la
a
(IV) The threshold frequency for a metal surface is ν . If the radiation of 0

frequency 3ν0 illuminates the surface, the maximum kinetic energy
(KE) of photoelectrons is E1. If the frequency were increased to 60,

E1
the maximum KE of the photoelectrons becomes E2. Then E  equals
 2
m
(A) 1/3
c o m (B) 1/2
m .co
(C) 2/5 . s e
em
(D) 3/4
s g l a
l a OR a
agLet m be the slope of the graph line for metal B. If e is the value of
electron charge, then Planck’s constant ‘h’ is given by

1
(A) me (B) me

m e
(C) e (D) m
m
.co
s em SECTION – E
g lofa two point charges q and –q separated
a
31. (a) An electric dipole consists

by a distance 2a. Derive an expression for the electric field E due to
this dipole at a point distant r from the centre of the dipole on the
equatorial plane. Write the expression for the electric field at a far
off point, i.e. r >> a.

(b) m
A dipole is placed in x-y plane such that charges q and –q are located
o
m c
. field
.co
at x = a and x = b respectively. There exists an electric
m
e torque 
em
 N
l s
E = 2 ^i C in the region. Calculate the force Faand
 

las a g
ag experienced by the dipole. 5

OR

~55/1/1~ { } 27  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 27 of 32

(a) E1  E2    (emf)         r1  r2

                
       emf          
(b)  (a)        emf E  3E   
  R      2R        2R   
     

32. (a)                
  5

(b)   L1, L2  L3       40 cm        
L1  L2  L2  L3      120 cm  20 cm    

 L1    80 cm       

             

(a)                
               
 
(b)      10 cm          
            

33. (a)   -      5

(b) l  A     N         

-       

~55/1/1~ { } 28  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 28 of 32

m
m .co

m .co s em
se g la
a
(a) Two cells of emf E and E with internal resistances r and r
1 2 1 2

respectively, are connected in parallel by connecting their positive
terminals together and negative terminals together. Deduce an
expression for equivalent emf and equivalent internal resistance of
the combination.
m
.co
(b) A parallel combination, as stated in (a) above, of two cells of emfs E
m
m .co
and 3E and internal resistances R each is connected across a
s e m
e
resistance 2R. Find the current that flows through resistance 2R.
s l a
g l a ag
a
32. (a) Using the relation for refraction at a curved spherical surface, derive
the expression for lens maker’s formula. 5

(b) Three lenses L1, L2 and L3, each of focal length 40 cm, are placed
coaxially. The distance between L1 and L2 and between L2 and L3 are

m
120 cm and 20 cm respectively. An object is kept at a distance of 80
cm to the left of lens L1.
m .co
s e
la
Find the distance of the final image formed from the object.
g
a OR
(a) Draw a ray diagram to show the image formation by a concave
mirror when the object is kept between its focus and the centre of
curvature. Using this diagram, derive the mirror formula.

(b) A concave mirror produces a two times magnified virtual image of an
object kept 10 cm in front of it. Calculate the focal length of the m
m .co
.co
mirror.
e m
em 33. (a) State Faraday’s law of electromagnetic induction. glas
las a 5

ag (b) Derive an expression for the self-inductance of an air-filled long
solenoid of length l and cross-sectional area A having N turns.

~55/1/1~ { } 29  P.T.O P.T.O.

m .
.co s e m
s em l a
g la ag
a For more Question Papers, Sample Papers, Notes & Syllabus visit Page 29 of 32

(c) 50 cm          , 60 rpm   

, 4.0 mT                  
  (emf)   

(a)                
                
        
(b)             1 : 5   
   5 kW  200 V     ,    :
(i)    , 
(ii)  
___________

~55/1/1~ { } 30  P.T.O

For more Question Papers, Sample Papers, Notes & Syllabus visit Page 30 of 32

m
m .co

m .co s e m
se g l a
a
(c) A conducting rod of length 50 cm, with one end pivoted, is rotated
with angular speed of 60 rpm in a uniform magnetic field of 4.0 mT
directed perpendicular to the plane of rotation of rod. Find the emf
induced in the rod.

OR
m
(a) m
Draw a labelled diagram of a step-up transformer. State the .co
.co
principle on which it works and obtain the ratio of secondary voltage e m
s em voltage in terms of number of turns and currents in the glas
to primary
g la coils.
two
a
a
(b) The ratio of the number of turns in the primary to the secondary of
an ideal transformer is 1 : 5. If 5 kW power at 200 V is supplied to
the primary, find

(i) current in the primary, and

(ii) output voltage.
m
. co
___________
s em
g la
a

m
m .co
m .co s e m
s e g l a
g la a
a

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m .
.co s e m
s em l a
g la ag
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