EE-305

BOARD DIPLOMA EXAMINATION, (C-16)OCT/ NOV -2017

DEEE- III SEMESTER EXAMINATION

ELECTRICAL AND ELECTRONICS MEASURING INSTRUMENTS 
Time: 3 hours

Total marks: 80M

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PART-A

10X3=30

Instructions:-

1. Answer all questions
2. Each question carries three marks

1. State different types of measuring instruments based on their working principle.
2. State
(a) Accuracy
(b) Resolution.
3. Calculate the shunt required to extend the range of moving coil ammeter, which takes 20ma to measure 20a.if the resistance of the coil is 0.075ohms.
4. Define creeping error and write its adjustment.

5. Classify the resistance based on their values.

6. Write the applications of potentiometer.
7. Define
a) Transducer
(b) sensor
8. Write the applications of thermistors.
9. Draw the block diagram of digital voltmeter.
10. Write advantages of digital energy meter.

PART-B

5x10=50M

Instructions:-

1. Answer any five questions
2. Each question carries ten marks

11.
(A) Explain construction and working of PMMC.
(B) State the errors present in moving iron instrument.
12. Explain construction and working of dynamometer wattmeter with neat sketch.
13.
(A) State the precautions to use the current transformer in measuring instruments.
(B) A 230v, 1-φ energy meter has a constant load current of 4a passing through the meter for 5hrs at upf. If the meter disc makes 1104 revolutions during this period, what is the meter constant?
14. Explain construction and working of 3-φ energy meter with neat sketch.
15. Explain measurement of insulation resistance by using Megger with neat sketch.     
16.
(A) Write the disadvantages of thermo couple.
(B) Explain construction and working of LVDT with neat sketch.
17. Explain working of digital multimeter with neat sketch
18.
(A) State different torques developed in measuring
instruments.
(B) Compare Analog and Digital measuring instruments.