Kerala Plus Two Question Paper 2025 Physics

KERALA BOARD

QUESTION
PAPER
2025
DOWNLOAD PDF
Kerala Board of Public
Examinations

SY-424
Reg. No. : ......................................

Name : ...........................................

SECOND YEAR HIGHER SECONDARY EXAMINATION, MARCH 2025

Part – III Time : 2 Hours
PHYSICS Cool-off time : 15 Minutes
Maximum : 60 Scores

General Instructions to Candidates :
 There is a ‘Cool-off time’ of 15 minutes in addition to the writing time.
 Use the ‘Cool-off time’ to get familiar with questions and to plan your answers.
 Read questions carefully before answering.
 Read the instructions carefully.
 Calculations, figures and graphs should be shown in the answer sheet itself.
 Malayalam version of the questions is also provided.
 Give equations wherever necessary.
 Electronic devices except non-programmable calculators are not allowed in the
Examination Hall.
 
    15  ‘  ’ .
 ‘  ’    
 .
      .
    .
  , , ,   
.
   .
    .
     
    .

SY-424 1 P.T.O.

Answer any 5 questions from 1 to 7. Each carries 1 score. (5  1 = 5)
1. The electrostatic force per unit charge is known as _____ .
(a) Electric current
(b) Electric potential
(c) Electric field

2. A circle of radius r is drawn with a charge +q placed at the centre. The work done in
moving a point charge once around the circumference of the circle is _____.

3. Which of the following gives the polarity of the induced emf ?
(i) Biot-Savart Law (ii) Lenz’s Law
(iii) Ampere’s circuital Law (iv) Fleming’s right-hand Rule

4. The frequencies of gamma-rays, ultraviolet rays, and X-rays are v 1, v2 and v3
respectively. Then
(i) v 1 = v2 = v3 (ii) v1 > v3 > v2
(iii) v1 > v2 > v3 (iv) v3 > v2 > v1

5. If radius of first electron orbit of hydrogen is r 0, radius of second electron orbit of
hydrogen is _____.

6. Two thin lenses of power + 4D and – 2D are in contact. The focal length of the
combination is _____.

7. _____ process is responsible for the production of energy in sun. (Nuclear fission /
Nuclear fusion)

Answer any 5 questions from 8 to 14. Each carries 2 scores. (5  2 = 10)

ml
8. Show that the resistance of a conductor can be expressed by R = , where symbols
ne2A
have their usual meanings.

9. Relative permeability of a material r < 1, identify the magnetic material. Write the
relation between relative permeability and magnetic susceptibility.

SY-424 2

1  7    5  .
1  . (5  1 = 5)
1.       _____
.
(a)  
(b)  
(c)  

2.  r     +q  . 
       
 _____ .

3.     ..    .
(i) -  (ii)  
(iii)    (iv)    

4.      
   v1, v2  v3 
(i) v 1 = v2 = v3 (ii) v 1 > v3 > v2
(iii) v1 > v2 > v3 (iv) v3 > v2 > v1

5.       r0 
     _____ .

6.  + 4D  – 2D     .
    _____ .

7.    _____  .
( / )

8  14    5  .
2  . (5  2 = 10)
ml
8.    R = 2   
ne A
.    .

9.    , r < 1 
.   
  .
SY-424 3 P.T.O.

10. The instantaneous current and voltage of an a.c. circuit are given by i = 10 sin 314t
Ampere and v = 50 sin (314t + /2) Volt.
What is the
(a) phase difference between voltage and current ? (1)
(b) power dissipation in the circuit ? (1)

11. (a) Which electromagnetic wave is used in cellular phones to transmit voice
communication ? (1)
(b) In the process of charging of a parallel plate capacitor, the current produced
between the plates of the capacitor is
dE 1 dE
(i) 0 (ii)
dt 0 dt
dE 1 dE
(iii) 0 (iv)
dt 0 dt
where symbols have their usual meanings. (1)

12 (a) Define wavefront. (1)
(b) Figure shows a plane wavefront incident on a convex lens, draw the
corresponding refracted wavefront. (1)

13. What is meant by ionisation energy ? Write its value for hydrogen atom.

14. The carbon isotope 6C12 has a nuclear mass of 12.000000 u. Calculate the binding
energy of its nucleus. Given mp = 1.007825 u; mn = 1.008665 u, 1 a.m.u. (u) = 931 MeV.

Answer any 6 questions from 15 to 21. Each carries 3 scores. (6  3 = 18)
15. (a) Define electric dipole moment. (1)
(b) Write an expression for torque acting on an electric dipole placed in a uniform
electric field. When will it become maximum ? (2)

SY-424 4

10.  ..     .
i = 10 sin 314t, , v = 50 sin (314t + /2) .
(a)       ? (1)
(b)     ? (1)

11. (a)     
   ? (1)
(b)       ,
    .
dE 1 dE
(i) 0 (ii)
dt 0 dt
dE 1 dE
(iii) 0 (iv)
dt 0 dt
   . (1)

12 (a)  () . (1)
(b)   ( )  
  .  
 . (1)

13.      ?
    .

14.   6C12   12.000000 u . 
   . mp = 1.007825 u; mn = 1.008665 u,
1 a.m.u. (u) = 931 MeV.

15  21    6  .
3  . (6  3 = 18)
15. (a)    . (1)
(b)      
    .  
  ? (2)
SY-424 5 P.T.O.

16. (a) What is equipotential surface ? (1)
(b) Write two properties of equipotential surfaces. (2)

17. (a) What is the working principle of a moving coil galvanometer ? (1)
(b) How will you convert a galvanometer into an ammeter ? (1)
(c) An ammeter is always connected in series with a circuit. Why ? (1)

18. Using Huygens concept of wavefront, derive Snell’s law of refraction.

19. (a) Which one of the following is the correct graph showing the variation between the
maximum kinetic energy (K.E.max) of the emitted photoelectrons and the
frequency of incident radiation (v) for a given photosensitive surface ? (1)

(i) (ii)

(iii) (iv)

(b) A photosensitive surface has a work function of 2.00 eV. Find the maximum
kinetic energy of electrons ejected from this surface by radiation of wavelength
300 nm. (Planck’s constant, h = 6.63  10–34 J s) (2)

20. (a) State Gauss’s law in magnetism. (1)
(b) A short bar magnet placed with its axis at 30° with a uniform external magnetic
field of 0.3 T experiences a torque of magnitude equal to 5  10–2 J. What is the
magnitude of the magnetic moment of the magnet ? (2)

21. With the help of a circuit diagram, explain the working of a half wave rectifier. Draw
the input and output waveforms.

SY-424 6

16. (a)     ? (1)
(b)      . (2)

17. (a)        ? (1)
(b)       ? (1)
(c)       .
 ? (1)

18.   ,   
.

19. (a)      
   (K.E.max) 
 (v)    .
    ? (1)

(i) (ii)

(iii) (iv)

(b)       2.00 eV .
 300 nm      
    
. ( , h = 6.63  10–34 J s) (2)

20. (a)    . (1)
(b) 0.3 T     
 30°    
 5  10–2 J .     ? (2)

21.      
 .     .
SY-424 7 P.T.O.

Answer any 3 questions from 22 to 25. Each carries 4 scores. (3  4 = 12)
22. (a) Obtain an expression for the equivalent capacitance when two capacitors C 1 and
C2 are connected in parallel. (2)

(b) Given graph shows variation of charge ‘q’ with potential difference ‘V’ for two
capacitors C1 and C2. Both the capacitors have same plate separation but plate
area of C2 is greater than that of C1. Which line (X or Y) corresponds to C1 and
why ? (2)

23. (a) Kirchhoff’s voltage law is in accordance with the conservation of
(i) mass (ii) energy
(iii) momentum (iv) charge (1)
(b) With the help of diagram, arrive at the Wheatstone’s principle. (3)

24. (a) What is the working principle of an a.c. generator ? (1)
(b) With the help of a diagram, explain theory and working of an a.c. generator. (3)

25. (a) Draw a ray diagram of simple microscope showing image formation at the least
distance of distinct vision (D). (2)
(b) The magnification of a compound microscope is 20. The focal length of the
eyepiece is 5 cm and the image is formed at the near point (25 cm). Find the
magnification of objective lens. (2)

Answer any 3 questions from 26 to 29. Each carries 5 scores. (3  5 = 15)
26. (a) A spherical shell of radius ‘R’ is uniformly charged with charge ‘+q’. Using
Gauss’s law find the electric field intensity at a point
(i) Outside the spherical shell. (2)
(ii) On the surface of the spherical shell. (1)

SY-424 8

22  25    3  .
4  . (3  4 = 12)
22. (a)     C1   C2
      . (2)
(b)   C1  C2   ‘q’ 
 ‘V’   . 
      C2  
 C1  .   (X or Y) C1  .
 ? (2)

23. (a)      
.
(i)  (ii) 
(iii)  (iv)  (1)
(b)      . (3)

24. (a)  ..     ? (1)
(b)    ..  
 . (3)

25. (a)   (D)    
        . (2)
(b)      20 . 
    (25 cm) 
     5 cm  .
    ? (2)

26  29    3  .
5  . (3  5 = 15)
26. (a) R    +q    
  
(i)    (2)
(ii)      
  . (1)

SY-424 9 P.T.O.

(b) A point charge causes an electric flux –2  1014 Nm2/C to pass through a
spherical Gaussian surface. (0 = 8.85  10–12 C2 N–1 m–2)
(i) Calculate the value of the point charge. (1)
(ii) If the radius of the Gaussian surface is doubled, how much flux would pass
through the surface ? (1)

27. (a) What is Lorentz force ? (1)
(b) The figure shows the path of motion of a charged particle (+q) in a uniform
magnetic field :

(i) What will be the direction of magnetic field with respect to the velocity of
the charged particle ? (1)
(ii) Show that the frequency of revolution of charged particle is independent of
the radius of the path. (2)
(iii) Is there any change in kinetic energy of the charged particle ? Explain. (1)

28. (a) With the help of a phasor diagram, find the impedance of a series LCR circuit. (3)
(b) A series LCR circuit is connected to an ac source of variable frequency as shown
in figure below. At what frequency the impedance of this circuit will be minimum ? (2)

29. (a) Draw the path of a light ray, through the prism, which suffers minimum deviation.
Mark the angle of deviation, angle of incidence and angle of emergence in the
figure. (2)
(b) Using the above diagram, show that sum of the angle of deviation and the angle of
the prism is equal to the sum of the angle of incidence and angle of emergence. (2)
(c) What do you mean by angle of minimum deviation ? (1)
____________
SY-424 10

(b)     –2  1014 Nm2/C    
   . (0 = 8.85  10–12 C2 N–1 m–2)
(i)    . (1)
(ii)       
  . (1)
27. (a)     ? (1)
(b)        
 (+q)   .

(i)      
  . (1)
(ii)     
   . (2)
(iii)     
 ? . (1)
28. (a)   LCR   
  . (3)
(b)    ..   LCR
    .
       ? (2)

29. (a)       
  .
 ,    
 . (2)
(b)     
    
  . (2)
(c)       
 ? (1)
____________
SY-424 11 P.T.O.

SY-424 12