ieee quiz.doc1

8/7/2019 IEEE quiz.doc1

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Valliammai Engineering CollegeSRM Nagar, Kattankulathur

QUEST11

1. The potential difference required to pass a current 0.2 A in a wire of resistance20W is ____.

1.100 V 2.4 V 3.0.01 V 4.40 V2. Kilowatt - hour is the unit of ______________.

1.potential difference 2.electric power 3.electrical energy 4.charge

3. When there is an electric current passing through a wire, the particles movingare _____________.

1.electrons 2.protons 3.atoms 4.ions

4. In a D.C.motor if the inductance of the field or armature winding is high, thenthe time constant is

1. High 2. Low 3. Not affected 4. High when the current increases

and low when the current decreases.

5. Flemings left hand rule is applicable for:

a) dc generator b) dc motor c) alternator d) Transformer

6. The emf produced in the dc generator is ____ induced emfa) Statically b) Dynamically c) magnetically d) Electrostatically

7. In which instrument the deflection depends on the average value

1. Moving iron meter 2.Rectifier instrument 3.Hot wire instrument 4.Moving coilinstrument

8. In two wattmeter method if Power factor is 0.5, one of the wattmeter will read

1. Zero 2.W/3 3.W/2 4.W/3

9.If a current of 1 amp passes through a lamp for 100 seconds, the number ofcoulombs of charge passing through the lamp in that time must be


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1.10 coulombs 2.15 coulombs 3.100 coulombs 4. 0.01 coulombs

10. If emf in a circuit is given by e= 100 Sin628t, then the maximum value ofvoltage and value of frequency are

1.100V,50Hz 2.100V,100Hz 3.502,50Hz 4.502,100Hz11.Which of the following transformer will be smallest in size

1.10KVa 50Hz 2. 10KVa 60Hz 3. 10KVa 100Hz 4. 10KVa 200Hz

12.Which of the following are true for a 3 phase delta connected circuit

1.Line voltage=Phase voltage 2.Line current = Phase current

3.Line current = 3 phase current 4. Line voltage = 1/3 phase voltage

13.A set of independent current measurements taken by four observers wasrecorded as 117.02mA, 117.11mA,117.08mA and 117.03mA. What is the range oferror?

1. 0.045 2. 0.054 3. 0.065 4. 0.056

14.Flemings right hand rule is applicable to

1.Generator 2.Motor 3.Transformer 4.None of these

15.The first power station operated by Edison is

1.AC 2.DC 3.Both AC & DC 4.None of these

16.The type of transmission used for sound in TV transmission is

1.AM 2.FM 3.PCM 4.PWM

17.What is NSEC?

1.National Safety Electrical Code. 2.National Society for Electrical & Computer.

3.National Society for Environmental Concern. 4.National Society of Engineering

Course.

18.What is maximum AC transmission voltage in india.

1.700KV 2.650KV 3.690KV 4.1200KV

19.The largest power plant in the world is located in


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1. Congo 2.India 3.U.K. 4.China

20.The output of a logic gate is 1 when all its input are at logic 0. The gate iseither,

1. a NAND (or) an Ex-OR Gate 2. a NOR (or) an Ex-OR Gate3. a NAND (or) an Ex-NOR Gate 4. a NOR (or) an Ex-Nor Gate

21.How many 1s are present in the binary representation of 3x512+7x64+5x8+3?

1.8 2.9 3.10 4.11

22.As the temperature is increased, the voltage across a diode carrying a constant

Current

1. Increases 2. Decreases 3. Remains constant 4. May increase (or) decreasesdepending upon the doping levels in the junction

23.Which one of the following oscillators is used for generation of lightfrequencies.

1.R.C.Phase Shift 2.Wien bridge 3.L.C.oscillator 4.Blocking oscillator

24.A semiconductor that is electrically neutral

1. has no majority carriers 2. has no minority carriers

3. has no free charge carriers 4. has equal amount of +ve & -ve charges.

ANS:4

25.A multivibrator produces

1.Pure sine wave

2.Square waves

3.Distorted sine waves

4.Sawtooth voltages

ANS:3

26.The resistivity of semi-conductor

1. Increases as Temperature increases


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2. Decreases as Temperature increases

3. remains constant even when temperature varies

4. None of the above

ANS:2

27. Which device automatically interrupts the supply in the event of surges

1.Earthing Switch

2.Series reactor

3.Isolator

4. Circuit breaker

ANS : 4

28.Vande Graaff generators are useful for

1. Very high voltage & low current applications

2. Very high voltage & high current applications

3. Constant high voltage & current applications

4. High voltage pulses only

ANS:1

29. A driver maintains the speed of a car at 50Kmph. Here the feedback element is

1.Steering wheel

2.Needle of the speedometer

3.Eyes

4.All of these

ANS:2

30.An automatic washing machine is

1. A single feedback control system

2. A multi feedback control system


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3. An open loop control system

4. None of the above.

ANS: 3

31.Most suitable numerical method to solve electrostatic field problem is

1. Laplace equation method

2. Charge simulation method

3. Finite difference method

4. Resistance analog method.

ANS: 2

32. Tap changing transformers are used for

1. Stepping up the voltage

2. Stepping down the voltage

3. Both stepping up & stepping down the voltage

4. Supplying low voltage current for instruments

ANS: 3

33. Which of the following is not the distribution system normally used

1. 3-phase 4 wire

2. 3-phase 3 wire

3. Single phase 3 wire

4. Single phase 4 wire

ANS: 4

34. Skin effect depends on

1. Size of the conductor

2. Frequency of the current

3. Resistivity of the conductor material


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4. All of the above

ANS: 4

35. Material generally used for bus bar is

1. Copper 2. Steel 3. Aluminium 4. Tungsten

ANS: 3

36. Example for piezo-electric material(a) Rochelle salt (b) Lead zirconate (c) Potassium niobate (d) Barium Titaniumoxide

ANS: 2

37. Units for electric field strength(a) A/cm2 (b) mho/meter (c) cm2/V.s (d) V/cm

ANS;3

38. The motor used in electric toys is

1.Split phase motor

2. Permanent capacitor motor

3.Shaded pole motor

4.Capacitor start motor

ANS:3

39. Moving coil in dynamometer wattmeter connecteda) In series with fixed coil

b) Across supplyc) In series with loadd) Across load

Ans: Across supply

40. In an induction machine, if the air gap increaseda) Speed will be reduced

b) Efficiency will be improvedc) Power factor will be loweredd) Breakdown torque will be reduced


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Ans: Power factor will be lowered

41. Thermocouple is used to measurea) AC

b) DCc) Bothd) None

Ans: Both

42. Voltage feed back amplifier is a

a) Shunt-Shuntb) Shunt-Series

c) Series-Shuntd) Series- Series

Ans: Shunt-Shunt

43. The motor used in household refrigerators is

(A) dc series motor

(B) dc shunt motor

(C) universal motor

(D) single phase induction motor.

ANS:D

44. Noise in an electric motor may be due to

(A) cooling air

(B) magnetic effects

(C) bearings

(D) all of the above.


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ANS:D

45. In a hysteresis motor, the position of shaded pole with respect to main poledetermines

(A) speed of motor

(B) direction of rotation

(C) hysteresis loss

(D) no load rpm.

ANS:2

46. Which motor is generally used in tape recorders ?

(A) Universal motor

(B) Reluctance motor

(C) Split phase motor

(D) Hysteresis motor.

ANS:4

47. Synchronous motor can operate at(A) Lagging power factor only(B) Leading power factor only(C) Unity power factor only(D) Lagging, leading and unity power factor only.

ANS:D

48. Any physical system which does not automatically correct for variation inits output, is called ?

a) open loop systemb) closed loop systemc) unstable system


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d) none of the above

ANS:(a)

49.open loop control system is one in which the control action ?

a) depends on the input signal

b) is independent of the desired output

c) depends on system variables

d) depends on system size

ANS:(b)

50.Which of the following is used as a passive component in an electroniccircuit ?

a) vaccum diode b) Zener diode

c) inductor d) SCR

ANS: C

ieee quiz.doc1

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