ELECTRONIC MEASUREMENTS & INSTRUMENTATION PAPER 2

DOWNLOAD ELECTRONICS ENGINEERING PREVIOUS YEARS QUESTION PAPERS B.TECH PTU

ELECTRONIC MEASUREMENT & INSTRUMENTATION EC 307 5th Sem May 2k5

Max Marks 60

Note: Section A is compulsory. Attempt any Four questions from Section B and two from Section C. Assume any missing data. Make necessary assumptions wherever required.

Section A Marks 2 each

1.

• What precautions must be taken when using a sampling oscilloscope?
• What are the advantages of dual trace over dual beam for multiple-trace oscilloscopes?
• What is Harmonic Distortion?
• What is the dynamic range of a spectrum analyser with a third-order intercept point of +25 dBm and a noise level of -85 dBm?
• What are the important functions performed by instrument transformers?
• Why is sensitivity of the a.c. scales of a multimeter less than the d.c. section?
• What is strain gauge? Name four resistance materials for use in wire and foil gauges.
• Compare LED and LCD in respect of:

(i) construction materials
(ii) construction principle

• What are the advantages and disadvantages of piezoelectric transducer?
• What are the different methods of data transmission?

Section B Marks 5 each

2. Describe with diagrams the construction of an LVDT and explain its working principle.

3. How does the digital storage oscilloscope differ from the conventional storage oscilloscope using a storage cathode ray tube? What are the advantages of each?

4. Compute the value of self-capacitance of a coil when the following measurements were made. At frequency f1= 2 MHz the tuning capacitor is set at 450 p.f. When the frequency is increased to 5 MHz, the tuning capacitor is tuned at 60 p.f.

5. If a digitizing oscilloscope is to have a 6-bit resolution in both the horizontal and vertical axes and is to display transients at a rate of 1 ms per division for a display of 10 divisions, what is the speed required of the input A/D converter?

6. Provide a comparison between hydraulic and pneumatic transmission and give applications of each. Suggest other methods of transmission along with their advantages over these two methods.

Section C Marks 10 each

7. What are the typical operating and performance characteristics of digital voltmeters? How are digital voltmeters classified? Give the block diagram of a staircase-ramp digital voltmeter and explain its working.

8. (a) What is gauge factor? A resistance strain gauge with a gauge factor of 2 is fastened to a member which is subjected to a strain of 1 x 10-6. If the original resistance value of the gauge is 130, calculate the change in resistance.
(b) Give the functional block diagram of the heterodyning wave analyzer and explain its working>

9. explain the working of an X-Y recorder with the help of a diagram. What are the important features of this instrument?