Goa Board Class 10 Question Paper 2025 Electronics

2025 III 17 0930 Seat No.

Time : 1½ Hours ELECTRONICS

(Pre-vocational)
Subject Code

S 1 0 4 3

Total No. of Questions : 4 (Printed Pages : 4) Maximum Marks : 40

INSTRUCTIONS : (i) All the questions are compulsory.

(ii) Figures to the right indicate full marks.

(iii) Draw a neat labelled diagram wherever necessary.

(iv) Answer each question on a fresh page.

1. (A) Answer the following in one word : 2

(i) Name the device that smooths out the AC variations in the

output of the rectified voltage in power supply.

(ii) Which device in a PA system converts electric wave into sound

wave ?

(B) Answer the following in brief : 6

(i) What is a rectifier ? Explain the working of a centre tap full

wave rectifier.

(ii) Name different types of full wave rectifier. What is the

advantage of using 4 diode rectifier instead of 2 diode rectifier ?

Draw the input and out waveform of a half wave rectifier.

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(C) Answer the following in short : 2

(i) Complete the block diagram given below with the names of the

three main components of a PA system.

2. (A) Answer the following in one sentence : 2

(i) What is mutually induced EMF ?

(ii) Name the type of losses occurs in the transformer due to

alternating magnetic fields.

(B) Answer the following in brief : 6

(i) Why transformers requires very little care and maintenance ?

Give one point of difference between core type and shell type

transformer.

(ii) Mr. Jumani repairs old loudspeakers. He wanted to repair the

loudspeaker shown in the diagram below. After careful

examination he found that part A and part B marked in the

diagram below needs replacement.

Answer the following with respect to the above statement :

(a) Identify and name the loudspeaker.

(b) Name the parts A and B of the speaker.

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(c) What is the function of part C in the diagram ?

(C) Answer the following in short : 2

(i) Explain in brief the working of a capacitor speaker.

3. (A) Answer the following in one or two words or sentences : 2

(i) Define Frequency (F)

(ii) Give one disadvantage of Ribbon microphone.

(B) Answer the following in short : 4

(i) A sound wave of frequency 300 Hz, moves at the velocity of

330m/s. Calculate its time period and wavelength.

(ii) What is a tuning circuit ? Name two type of tuning circuits.

(i) Draw a circuit symbol of crystal microphone. Explain with a

neat labelled diagram the working of a crystal microphone.

(ii) Draw a circuit symbol of Carbon microphone. Explain with a

neat labelled diagram the construction of a dynamic microphone.

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4. (A) Answer the following in one sentence : 2

(i) State Kirchhoff current law.

(ii) Name the two elements of semiconductor.

(B) Answer the following in brief : 4

(i) Two resistors of 8 each are connected in parallel. Draw a

suitable circuit diagram to show the connection. Calculate the

effective resistance of the circuit.

(ii) Draw the symbols to differentiate NPN and PNP transistors.

What is the atomic number of germanium and silicon ?

(i) Give one example of a trivalent and pentavalent elements used

for doping semiconductor material. Explain how N-type

semiconductor material is obtained.

(ii) What is the important characteristic of a diode ? With the help

of a neat diagram explain the working of a transistor.

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