EE6352 ELECTRICAL ENGINEERING AND INSTRUMENTATION

ECE IIYR QUIZ -I

1. Why Electronic instruments are preferred? (A)they have no indicating part (B) low resistance in parallel circuit(C) very fast response (D) high resistance in series circuit

2. Which parameter is related with the unit Decibel?

A) Power B) Impedance C) Frequency D) Power ratio

3. What is the output voltage of a typical thermocouple?

A) less than 100mv B) greater than 1V C) Thermocouples vary resistance, not voltage.D) Thermocouple vary voltage

4. What is the effect by using connections to a thermocouple?

A. Can produce an unwanted thermocouple effect, which must be compensated

B. Produce an extra desirable thermocouple effectC. Must be protected, since high voltages are

presentD. produce an extra desirable thermocouple effect

and must be protected, since high voltages are present

5. Which of the following performance specification applies to a sample- and-hold circuit?

A. Aperture time B. Aperture drop C. Feedback D. Acquisition jitter

6. What is the limiting error of an ammeter of 0-25 A range has a guaranteed accuracy of 1% of full scale reading if the current measured is 5 A?

A. 2% B.2.5% C. 4% D. 5%

7. What is the power factor of the load in a 3

phase power measurement by 2 wattmeter method, the reading of one wattmeter is zero?

A. 1 B. B. 0.5 C. 0 D. 0.8

8. Which of the following is not a part of CRO?A. Cathode B. Grid C. Accelerating anode D. X-Y plates

9. What is the angle δ for a mica capacitor?A. 25° B. 15° C. 5° D. D.1°

10. What is the resolution of a digital voltmeter has a read out range from 0 to 999 counts.,if the full scale reading is 9.999 V?

A. 1V B. 0.01VC. 1mVD.1 μV

11. What is the moving part of a linear variable differential transformer?

A. Primary B. Secondary C. Diaphragm D. Core

• 12. What should be the wire made as, to increase Q factor of a coil?

• A. long • B. Thin • C. thick • D. long and thin

• 13. What is the dimension of the magnetic Flux density?

• A. MI-1T-2 • B. M-1I-2T-2 • C. ML-3T-2 • D. MI-1T-3

14. Which category does the household energy meter belongs to ?

A. Indicating instrument B. Recording instrument C. Integrating instrument D. Pointing instrument

15. What is the reading of voltmeter, if a full wave rectifier type meter is used to measure the wave shape shown in figure and the voltmeter is calibrated to read rms value of sine wave?

• A. 50/√2 V• B. 100/√2 V • C. 100V • D. 111V

16. What is the value of shunt resistance, if a moving coil instrument has a resistance of 0.5 Ω and a full scale deflection of 0.1 A and to onvert it into an ammeter of 0-10 A?

• A. 0.004 Ω • B. 0.005 Ω • C. 0.05 Ω • D. 0.1 Ω

17. Why Potentiometer method of dc voltage measurement is more accurate than direct measurement using a voltmeter?

• A. It loads the circuit to maximum extent • B. it loads the circuit moderately • C. it does not load the circuit at all • D. it uses centre zero galvanometer instead of

Voltmeters

18. Which of the following is true about an impulse voltage?

A. It is unidirectional voltage.B.Chopped impulse flashover doesnot occurC. Time taken to rise is equal to time taken to fall D. RMS value is 50% of average value

19. Which of the following are needed both for protection and metering?

• A. Wattmeters • B. Instrument transformers • C. Energy meters • D. Power factor meters

20. Which component can be added to a digital frequency counter to convert it to DVM?

• A.voltage controlled oscillator • B. D/A converter• C.Power amplifier • D. operational amplifier

• 21. What will be the reading when a dynamometer wattmeter is connected in ac circuit?

• A. V-A product • B. average power • C. peak power • D. instantaneous power

22. What is the main advantage of speed transducer using a drag cup rotor?

A. very high accuracy B. low energy requirement C. cheap construction D.lowpower

23. What is the quantity measured by a voltmeter using thermocouples?

A. rms value B. peak value C. average value D. peak to peak value

24. Which of the following measurements using a dc potentiometer do not require standardisation of potentiometer?

A. Measurement of unknown voltage B. Measurement of resistance C. Measurement of unknown current D. Calibration of voltmeter

25. Which of the following statement is correct for two wattmeters method of power measurement in 3 phase circuit?

A. Power can be measured by this method only for star connected loads

B. When two wattmeters have equal readings power factor is 0.5.

C. When power factor is 1, one of the wattmeters readings is zero

D. When the two wattmeter read equal and opposite, p.f. is zero

26. Which instrument is used to measure the output voltage in a thermocouple temperature transducer?

A. high resistance ammeter B. high resistance voltmeter C. high resistance milli-voltmeter D.low resistance ammeter

27. Which range of frequencies, a moving iron instrument gives correct reading?

A. low frequencies B. high frequencies C. only one frequency D. all frequencies

28. Where could be the Induction wattmeter used ?

• A. ac circuit only • B. dc circuit only • C. both ac and dc circuit • D. ac 3 phase only

29. What is the measured power of a dynamometer wattmeter when connected in ac circuit?

• A.rms power • B. average power • C. peak power • D.instantaneous power

30. Which component should be added to the The D'Arsonval- movement to converted into audio frequency ac ammeter ?

• A. Thermocouple • B.Transducer • C.Chopper • D.rectifier

31. What is the condition of bridge, If an inductance L is connected in one arm of bridge and resistance R1, R2, R3 in other three arms?

A. cannot be balanced B. can be balanced C. balanced for some specified value of frequencyD. balanced for some specific values of R1, R2, R3

32. What is LVDT?A.Pressure tranducer. B.displacement transducer C.velocity transducer D. acceleration ransducer

33. What is the potential of detector above earth potential in a Schering bridge?

A. few volts B. 10kV C. 1000V D. few milvolts

34. Which of the following instruments has non-linear scale?

1.Moving coil instrument 2.Moving iron instrument 3.Electrostatic instrument 4.Rectifier instrument

A. 2 only B. 2&3 only B. C. 2,3,1 D. 1,2,3,4

35. What is the dimensions of EMF?A. ML2I-1T-3 B. M-1T-3 C. ML2I-2T-3 D. ML3I-1T-3

36. Which of these has a magnetic brake?A. Thermocouple ammeter B. Energy meter C. Dynamometer D. Frequency meter

37. What is the Two sum of the numbers with range of doubt ,numbers are 131 ± 5 and 629 ± 3?

• A.760 ± 8 • B.760 ± 2 • C. 760 + 8 • D. 760 – 8

38. Which of the following option is correct for a schering bridge?

• Assertion (A): Schering bridge is a low voltage bridge.• Reason (R): Schering bridge is very commonly used for

measurement of capacitance.

• A. Both A and R are true and R is correct explanation of A• B. Both A and R are true but R is not correct explanation

of A• C. A is true R is false• D. A is false R is true

39. Which of the following option is correct for wein bridge? • Assertion (A): Wien bridge can be used for measuring frequency.• Reason (R): A frequency meter for 50 Hz system has a frequency

range of 40 to 60 Hz.A.

• A.Both A and R are true and R is correct explanation of A• B. Both A and R are true but R is not correct explanation of A• C. A is true R is false • D. A is false R is true

40.Which of these has poor overload capacity?• A. PMMC instrument • B. Hot wire instrument • C. Dynamometer instrument • D.Moving iron

41. What is the power factor of the load in 3 phase power measurement by two wattmeter method, both wattmeters had equal reading?

• A. 1 • B. 0.5 lagging • C. 0.5 leading • D. 0

42. Which instrument is based on induction principle?

A. Dynamometer wattmeter B. Induction wattmeter C. C. Energy meter D. D. Both B&C

43. What is the dimension of Magnetic field intensity?

• A. IL • B.I2L • C.IL-1 • D. IL-2

• 44. Which element acts as aprimary sensing element in a pressure gauge?

• A. Moving coil • B.Moving iron • C.Thermocouple • D. magnets

45.Which of the following is a dynamic characteristic of measurements?

• A. Accuracy • B.Precision • C.Speed of Response • D. sensitivity

46.What is the process of making an adjustment of scale to an international standard?

A. Marking B. Calibration C. Standardization D. D. Indication

47. What is the phase shift between 2signals, when two sinusoidal signals of equal frequency & amplitude applied for a Lissajous pattern?

A.zero B. 90 deg C either 0 or 180 deg D. either 0 or 180 deg

48. Which material is related with Thermistors?• A. Pure metals • B. Pure insulators • C. tintered mixture of metallic oxides. • D. pure semiconductors.

49. Which scale is related to the use of thermocouple meters for ac measurement?

A.Linear B.Square law C. logarithmic D. exponential

50.Which is the most commonly used moving iron instrument?

A. Repulsion type B. Attraction type C. Combination type D. DC type