Goa Board Class 12 Question Paper Mar 2019 Industrial Electronics and Instrumentation

2019 III 14 1000 Seat No.

Time : 2 Hours Industrial Electronics & Instrumentation
Subject Code

V 3 3 4
Total No. of Questions : 5 (Printed Pages : 4) Maximum Marks : 50

INSTRUCTIONS : (i) All questions are compulsory.

(ii) Answer each question on a fresh page.

(iii) Figures to the right indicate full marks.

(iv) Draw neat diagrams wherever necessary.

(v) Write the number of each question and sub-question

clearly.

1. (A) Fill in the blanks : 2×1=2

(i) Photo cell converts light energy in to ............... ................. .

(ii) Line regulation is percentage change in output voltage to change

in ................. .................... .

(B) Answer the following in brief : 2×3=6

(i) With the help of a neat block diagram, explain the working of

DC to DC converter.

(ii) With the help of a neat diagram, explain over light detector

circuit using SCR.

(C) Answer the following : 1×2=2

(i) With the help of a neat constructional diagram, explain working

of pn-junction photo diode.

2. (A) Define the following : 2×1=2

(i) Transducer

(ii) Photo conductive effect.

(B) Answer the following in brief : 2×3=6

(i) Draw the block diagram of CRO. Explain, delay line circuit and

power supply.

(ii) With the help of a neat diagram, explain the range extension

of DC voltmeter.

(C) Answer the following : 1×2=2

(i) State any two applications of Astable multivibrator using timer

IC NE555 and write its output time period formula.

3. (A) Fill in the blanks : 2×1=2

(i) When force or pressure is applied to the piezoelectric crystal, it

produces .................................... .

(ii) The instrument used to measure the intensity of light radiation

is called .......................................... .

(B) Answer the following in short : 3×1=3

(i) With the help of block diagram. Explain AF signal generator.

(C) Answer the following in detail : 1×5=5

(i) With the help of block diagram explain metal detector and state

any two applications of it.

Or

(i) Draw the block diagram of electrocardiogram (ECG) and explain

the function of each block.

4. (A) Answer the following in one word/sentence each : 2×1=2

(i) State the frequency calculating formula using CRO.

(ii) State the function of electron gun assembly in cathode ray

tube (CRT).

(B) Answer the following : 1×3=3

(i) Draw the pin configuration diagram of timer IC NE555 and

explain the function of pin no. 2 and pin no. 7.

(C) Answer the following : 1×5=5

(i) State any two applications of DC series motor and with the help

of circuit diagram explain the flux control method used to control

the speed of it.

Or

(i) State any two applications of DC shunt motor and with the help

of circuit diagram explain the armature resistance control method

used to control the speed of it.

5. Answer the following : 2×5=10

(1) State any two examples of active transducer and passive transducer.

(2) Draw a neat labelled diagram of capacitive transducer and state any

two applications of it.

(3) Why should resistor be connected in series with LED ? Name two types

of LED lamp driver circuits.

(4) State any two points of comparison between LED and LCD.

(5) State any two advantages of electronic timer over mechanical timer.