Goa Board Class 12 Question Paper June 2019 Electronic and Electrical Measurements

2019 VI 12 1430 Seat No.

Time : 2 Hours Electronic & Electrical Measurements
Subject Code

V 3 4 1
Total No. of Questions : 5 (Printed Pages : 4) Maximum Marks : 50

INSTRUCTIONS : (i) Answer each question on a fresh page.

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

clearly.

(iii) All questions are compulsory.

(iv) Figures to the right indicate full marks.

1. (A) Fill in the blanks : 2

(i) The current rating of Germanium diode is .............................. .

(ii) A neutral solution like pure water has a pH value of .......... .

(B) Answer the following : 6

(i) Draw a neat block diagram of AF Signal Generator and explain

in brief its working.

(ii) A moving coil voltmeter with an internal resistance of 400

has a range of 1 volt. The voltmeter range has to be increased

to measure upto 10 volts. Calculate the value of series resistance

required.

(C) Answer the following : 2

(i) With a neat diagram explain Eddy current damping.

2. (A) Define the following : 2

(i) Shunt Resistance

(ii) Gauge factor.

(B) Answer the following : 6

(i) Distinguish between single phase induction type Energymeter

and single phase induction type wattmeter (3 points).

(ii) With a neat diagram explain DC Tachometer Generator.

(C) Answer the following in short : 2

(i) Draw a neat block diagram of Electrocardiograph (ECG).

3. (A) Fill in the blanks : 2

(i) The CRO probe which is simplest and uses a shielded co-axial

cable is ......................................... .

(ii) The effect caused by contact potential at the junction in

Thermocouple is known as .............................. effect.

(B) Answer the following : 3

(i) What is a Megger ? Mention any four precautions to be taken

while using Megger.

(C) Answer any one of the following in detail : 5

(i) Draw neat labelled block diagram of Cathode Ray Oscilloscope

(CRO) and explain Time Base Generator.

Or

(ii) Draw a neat diagram of Cathode Ray Tube (CRT) and explain

Electron Gun Assembly.

4. (A) Answer the following : 2

(i) Define pH of a solution.

(ii) Name the bridge which is used to measure unknown inductance

having Q less than 10 (Q < 10).

(B) Answer the following : 3

(i) With a neat diagram explain Potentiometric transducer.

(C) Answer any one of the following in detail : 5

(i) With a neat diagram explain current transformer. Mention one

practical application of current transformer.

Or

(ii) With a neat diagram explain Photo-electric Tachometer. Mention

any one advantage of this Tachometer.

5. Answer the following : 10

(i) With a neat circuit diagram explain calibration of Ammeter using

potentiometer method.

(ii) Mention any four advantages of Digital multimeter over Analog

multimeter.

(iii) Draw a neat block diagram of output power meter.

(iv) With a neat diagram explain thermocouple.

(v) Draw a neat circuit diagram of Wheatstones bridge.