Kerala Plus Two Question Paper 2025 Electroncis Systems

KERALA BOARD

QUESTION
PAPER
2025
DOWNLOAD PDF
Kerala Board of Public
Examinations

SY-453
Reg. No. : ......................................

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

SECOND YEAR HIGHER SECONDARY EXAMINATION, MARCH 2025

Time : 2 Hours
Part – III Cool-off time : 15 Minutes
ELECTRONIC SYSTEMS
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-453 1 P.T.O.

Answer all questions from 1 to 4. Each carries 1 score. (4  1 = 4)
1. Cut off frequency of an RC low pass filter is _________.

 1 1 
2RC , 2RC , 2RC , 
 2RC

2. An Op-amp as a voltage follower has a voltage gain of _________.
(Unity, Zero, Infinity, Less than unity)

3. _________ is a BCD to 7-segment decoder IC.
(IC 741, IC 7476, IC 7408, IC 7447)

4. Which of the following is a universally adopted shape of cell in mobile communication ?
(Hexagon, Square, Circle, Triangle)

Answer any 10 questions from 5 to 16. Each carries 2 scores. (10  2 = 20)
5. A positive clipper removes the positive portion of the input signal. Draw the circuit
diagram of a positive clipper and explain its working.

6. Draw the frequency response curve of an ideal band pass filter whose lower cut off
frequency is 3 MHz and upper cut off frequency is 30 MHz.

7. Differentiate between positive feedback and negative feedback.

8. What are the different steps in IC fabrication ?

9. Classify ICs based on the integration of components.

10. Draw the pin configuration of IC 741.

11. Write any two advantages of switched power supply over linear power supply.

12. Draw the block diagram of JK master slave flip-flop.

SY-453 2

1  4    . 1  .
(4  1 = 4)
1.  RC      _________ .

 1 1 
2RC , 2RC , 2RC , 
 2RC

2.  Op-amp      _________
.
(Unity, Zero, Infinity, Less than unity)

3. _________  BCD to 7-segment decoder IC .
(IC 741, IC 7476, IC 7408, IC 7447)

4.  ,   
 ________ .
(Hexagon, Square, Circle, Triangle)

5  16    10  .
2  . (10  2 = 20)
5.        .
      .

6.     3 MHz      30 MHz 
        
.

7.  -  -   .

8. IC     ?

9.    IC  .

10. IC 741    .

11. Linear power supply   switched power supply   
 .

12. JK master slave -   .
SY-453 3 P.T.O.

13. Compare TTL and CMOS logic family.

14. Draw the block diagram of a 3 bit SISO shift register.

15. Draw the structure of an optical fiber.

16. Give one example for 8 bit processor and 16 bit processor.

Answer any 8 questions from 17 to 26. Each carries 3 scores. (8  3 = 24)

17. The input and output waveform of a circuit is shown in the figure below.

(a) Identify the circuit (1)
(b) Draw the circuit diagram. (2)

18. (a) What determines the frequency of oscillation of an LC oscillator ? (1)
(b) Draw the circuit of a Colpitts oscillator. (2)

19. Draw a circuit to add three voltages V1, V2 and V3 using Op-amp. Also obtain the
equation for output voltage.

20. (a) _________ is used to convert dc into ac. (1)
(b) Draw its block diagram. (2)

21. Draw the logic circuit of a 4 : 1 multiplexer and write its truth table.

22. Explain public address system using block diagram.

SY-453 4

13. TTL, CMOS    .

14. 3 bit SISO     .

15.    .

16. 8 bit  16 bit    .

17  26    8  .
3  . (8  3 = 24)

17.        .

(a)   . (1)
(b)   . (2)

18. (a)  LC     
 ? (1)
(b) Colpitts    . (2)

19. V1, V2, V3    Op-amp  
 . ,    .

20. (a) dc  ac   _________ . (1)
(b)    . (2)

21. 4 : 1        .

22.       .

SY-453 5 P.T.O.

23. (a) In radio communication AM stands for _______. (1)
(b) Draw the block diagram of AM radio transmitter. (2)

24. What are the basic components of a RADAR system ? Explain with block diagram.

25. (a) __________ is an example of optical transmitter. (1)
(b) Draw the block diagram of optical fiber communication system. (2)

26. (a) CT scanner and MRI scanner are _________ group equipments. (1)
(b) Compare them. (2)

Answer any 3 questions from 27 to 31. Each carries 4 scores. (3  4 = 12)

27. (a) If the input of an integrator is a square wave, its output is _________ wave. (1)
(b) Draw its circuit diagram and write design rules. (3)

28. (a) A monostable multivibrator has _________ stable state and _________ quasi
stable state. (1)
(b) Draw a circuit to generate square wave using IC555. (3)

29. (a) Construct a clocked SR flip-flop using NAND gate and write its truth table. (3)
(b) What is the drawback of SR flip-flop and how can we eliminate this ? (1)

30. (a) ________ converts sound signal into electrical signal. (1)
(b) Draw the cross sectional view of the above transducer. (3)

31. (a) In mobile communication, CDMA stands for ________. (1)
(b) Write short notes on :
Wi fi
Bluetooth (3)
_____________

SY-453 6

23. (a)   AM    _______ . (1)
(b) AM     . (2)

24.       ?   
.

25. (a) __________    . (1)
(b)      
. (2)

26. (a) CT scanner, MRI scanner  _________  . (1)
(b)   . (2)

27  31    3  .
4  . (3  4 = 12)

27. (a)      ,  
_________  . (1)
(b)       . (3)

28. (a)    _________  
_________    . (1)
(b) IC555      . (3)

29. (a) NAND gate    SR flip-flop . 
  . (3)
(b) SR flip-flop    ?   . (1)

30. (a) ________      . (1)
(b)     . (3)

31. (a)   CDMA   ________ . (1)
(b)  :
Wi fi
Bluetooth (3)
_____________

SY-453 7 P.T.O.

SY-453 8