EC 307 5th Sem May 2005
ELECTRONIC MEASUREMENT & INSTRUMENTATION
Max Marks 60
Max Time 3 Hours
Note: Section A is compulsory. Attempt any Four questions from Section B and two from Section C.
Make necessary assumptions wherever required.
Section A Marks 2 each
1.
(10*2=20)
(a) What precautions must be taken when using a sampling oscilloscope?
(b) What are the advantages of dual trace over dual beam for multiple-trace oscilloscopes?
(c) What is Harmonic Distortion?
(d) 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?
(e) What are the important functions performed by instrument transformers?
(f) Why is sensitivity of the a.c. scales of a multimeter less than the d.c. section?
(g) What is strain gauge? Name four resistance materials for use in wire and foil gauges.
(h) Compare LED and LCD in respect of:
(i) construction materials
(ii) construction principle
(i) What are the advantages and disadvantages of piezoelectric transducer?
(j) What are the different methods of data transmission?
Section B Marks 5 each
(5*4=20)
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
(10*2=20)
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?
ELECTRONIC MEASUREMENT & INSTRUMENTATION
Max Marks 60
Max Time 3 Hours
Note: Section A is compulsory. Attempt any Four questions from Section B and two from Section C.
Make necessary assumptions wherever required.
Section A Marks 2 each
1.
(10*2=20)
(a) What precautions must be taken when using a sampling oscilloscope?
(b) What are the advantages of dual trace over dual beam for multiple-trace oscilloscopes?
(c) What is Harmonic Distortion?
(d) 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?
(e) What are the important functions performed by instrument transformers?
(f) Why is sensitivity of the a.c. scales of a multimeter less than the d.c. section?
(g) What is strain gauge? Name four resistance materials for use in wire and foil gauges.
(h) Compare LED and LCD in respect of:
(i) construction materials
(ii) construction principle
(i) What are the advantages and disadvantages of piezoelectric transducer?
(j) What are the different methods of data transmission?
Section B Marks 5 each
(5*4=20)
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
(10*2=20)
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?