# GTU previous year question paper- BE- VIIth SEM -Electrical and Electronics measuring Instruments -May/June- 2012

GTU previous year question paper

GUJARAT TECHNOLOGICAL UNIVERSITY

BE- VIIth SEMESTER–EXAMINATION – MAY/JUNE- 2012

Subject code: 170803

Subject Name: Electrical and Electronics measuring Instruments

Instructions:

1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) What is measurement standard? List out different types of standard. Explain voltage

standard in brief.

(b) Define: (1) Accuracy (2) Precision (3) Resolution (4) Sensitivity (5) Threshold

(6) Drift (7) Reproducibility

Q.2 (a) Define and explain different types of error that may occur in measurements.

(b) What do you mean by low, medium, and high resistances? State various methods for

measuring low resistance. Explain any one in detail.

OR

(b) An unknown resistance is measured by ammeter-voltmeter method. A voltmeter

having a sensitivity of 1000 _/V, reads 100 V on its 150 V scale when connected

across an unknown resistor in series with a milliammeter. When the milliammeter

reads 5mA. Calculate (i) the apparent resistance of the unknown resistor. (ii) the

actual resistance of unknown resistor. (iii) the error due to loading effect of voltmeter.

Q.3 (a) What are the problems associated with high resistance? Explain any one method for

measurement of insulation resistance of a cable.

(b) Explain Maxwell’s bridge for measurement of unknown inductance. Also determine

condition for balance with phasor diagram.

OR

Q.3 (a) Describe the working of Hay’s bridge for the measurement of inductance. Derive the

condition for balance and draw the phasor diagram.

(b) State different method for the measurement of unknown capacitance.

Q.4 (a) Explain construction and working of potential transformer. Also explain ratio and

phase angle error.

(b) Explain with neat diagram the working of digital voltmeter.

OR

Q.4 (a) Explain theory of working of current transformer with the help of phasor diagram.

(b) Explain with the help of block diagram the working of spectrum analyser.

Q.5 (a) What is an electrical transducer? What are the basic requirements of transducer? Give

the classification of transducer.

(b) Explain the construction and working of strain gauge. Also derive expression of

gauge factor.

OR

Q.5 (a) Explain construction and working of L.V.D.T.

(b) Explain construction and working of Hall effect transducer.