M3 Electrical Quiz 10 Random Questions Every Time (From 55 Total Questions)

 

Module - 3 Electrical

Quiz

 

1. The rotating part of a motor/generator is called?
   1.   commutator
   2.   armature
   3.   yoke
2. What is the purpose of the capacitor used in a single phase AC motor ?
   1.   Changing direction of motor
   2.   Provides a high starting torque
   3.   Smoothing Troque
3. The controlling phase on a two phase motor is of a ?
   1.   variable amplitude
   2.   fixed amplitude
   3.   direct current
4. In a two-phase induction motor there are ?
   1.   2 poles
   2.   4 poles
   3.   3 poles
5. In a synchronous motor, when the motor is running the slip is ?
   1.   100%
   2.   5%
   3.   0%
6. A capacitor in a single phase motor is to ?
   1.   prevent sparking at the switch
   2.   provide smoothing
   3.   provide a phase shift
7. Calculate the speed of a 400 Hz, 4 pole machine ?
   1.   6000 rpm
   2.   12,000 rpm
   3.   8000 rpm
8. A three-phase motor has the windings ?
   1.   90° apart
   2.   180°apart
   3.   120° apart
9. In an aircraft brushless alternator the armature is ?
   1.   star wound
   2.   delta wound
   3.   in series with the field
10. In a 2 phase generator, what angle are the phases to each other ?
    1.   0°
    2.   180°
    3.   90°
11. The SI unit of capacitance is ?
    1.   Farad
    2.   Volt
    3.   Ohm
12. Germanium and silicon have how many electrons in their outer shell?
    
    1.   8
    2.   6
    3.   4
13. A semi-conductor will have?
    
    1.   two electrons in the outer shell
    2.   four electrons in the outer shell
    3.   eight electrons in the outer shell
14. The symbol “Ω” represents ?
    1.   Watt
    2.   Ohm
    3.   Volt
15. An ammeter is always connected in?
    1.   Series
    2.   Parallel
    3.   Neither
16. A voltmeter is always connected in?
    1.   Series
    2.   Barometer
    3.   Both
17. Ohm’s law states that ?
    1.   R = V + I
    2.   V = I × R
    3.   I = R × V
18. Which of the following is 1 Amp?
    
    1.   1000 mA
    2.   1000 kA
    3.   1000 μA
19. The S.I. unit of magnetic flux density is the?
    
    1.   Henry
    2.   Weber
    3.   Tesla
20. The property of a material to accept lines of flux is called?
    
    1.   retentivity
    2.   reluctance
    3.   permeability
21. What is the SI unit of conductance?
    
    1.   Ohm-metre
    2.   Ohm
    3.   Siemen
22. What is the SI unit of resistivity ?
    
    1.   Ohms
    2.   Ohms/metre
    3.   Ohm metre
23. A thermocouple indicator is basically a type of ?
    1.   millivoltmeter
    2.   milliammeter
    3.   milliohmeter
24. A battery rated at 40 Ah will supply 200 mA for ?
    1.   20 hours
    2.   200 hours
    3.   5 hours
25. Two 12V 40 amp hour batteries connected in parallel will produce ?
    1.   12V 80 ah
    2.   24V 80 ah
    3.   24V 40 ah
26. In a mercury cell the steel casing is ?
    1.   The negative terminal
    2.   the positive terminal
    3.   Neither
27. The electrolyte in a nicad battery is ?
    1.   Cadmium hydroxide
    2.   Nickel hydroxide
    3.   Potassium hydroxide
28. A galvanometer measures ?
    1.   megohms
    2.   milliamps
    3.   millivolts
29. If voltage is 100V, resistance is 25 ohms, what is the current ?
    1.   2500 amperes
    2.   0.4 amperes
    3.   4 amperes
30. In a balanced Wheatstone bridge, across the centre of the bridge there is?
    1.   Current and voltage at maximum
    2.   No current flow
    3.   No voltage present at either end
31. Total resistance in a parallel resistor circuit, of R1 and R2 is ?
    1.   1/RT = 1/R1 + 1/R2
    2.   1/RT = (R1 * R2) ÷ (R1 + R2)
    3.   RT = 1/R1 + 1/R2
32. A 47 kilohm resistor has the following colour code ?
    1.   Orange, Violet, Red
    2.   Red, Orange, Yellow
    3.   Yellow, Violet, Orange
33. The phase difference between current and voltage in a pure inductive circuit is ?
    1.   0°
    2.   90°
    3.   180°
34. The reactance of a capacitor decreases when ?
    1.   Frequency increases
    2.   Frequency decreases
    3.   Capacitance decreases
35. When a conductor moves through a magnetic field, an EMF is induced due to ?
    1.   Electromagnetic induction
    2.   Mutual induction
    3.   Electrostatic induction
36. Lenz’s law states that ?
    1.   Induced current flows only in one direction
    2.   Induced EMF aids the cause producing it
    3.   Induced EMF opposes the cause producing it
37. In a transformer, eddy current losses can be reduced by ?
    1.   Increasing core size
    2.   Using laminated core
    3.   Using solid iron core
38. The primary purpose of a rectifier is to ?
    1.   Step up voltage
    2.   Convert DC to AC
    3.   Convert AC to DC
39. Kirchhoff’s voltage law states that ?
    1.   Total current entering equals current leaving
    2.   Total voltage around a loop equals zero
    3.   Power is equal to VI
40. The instrument used to measure insulation resistance is?
    1.   Voltmeter
    2.   Megger
    3.   Ohmmeter
41. One Picofarad is ?
    1.   1 * 10-6 farad
    2.   1 * 10-12 farad
    3.   1 * 1012 farad
42. Magnetic inclination is the least at the ?
    1.   poles
    2.   equator
    3.   isoclines
43. The unit of flux is the ?
    1.   Ampere turns / metre
    2.   Ampere turns
    3.   Weber
44. The symbol for flux density is ?
    1.   B(capital)
    2.   H(capital)
    3.   ø(phy)
45. If the rate of change of current is halved, mutual inductance will ?
    1.   Halve
    2.   Stay the same
    3.   Double
46. The electromagnetic brake coil in an actuator would be energised ?
    1.   only when the actuator is running
    2.   all the time in flight
    3.   only at the instant of starting and stopping
47. One purpose of a growler test is to determine the presence of ?
    1.   An out-of-round commutator
    2.   A broken field lead
    3.   A shorted armature
48. A series wound DC motor, the field has ?
    1.   many turns of thin wire
    2.   few turns of thick wire
    3.   few turns of thin wire
49. The voltage output of a generator is controlled by ?
    1.   varying the current of the output
    2.   varying the resistance of the output
    3.   varying the current of the field
50. A 6 pole wave-wound generator has ?
    1.   2 brushes
    2.   3 brushes
    3.   6 brushes
51. Commutator ripple can be reduced by ?
    1.   a resistor in series with the armature
    2.   increasing generator frequency
    3.   the use of a ripple filter
52. A shunt motor ?
    1.   is constant speed
    2.   has high starting torque
    3.   gives constant torque with variations in speed

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M-3 Electrical Final Practice Test [52 Question and 65 Minutes]

Module 03. Electrical

Final Practice Test

  

 

1. In what equipment is a photon radiated when an electron leaves a hole ?
   1.   LED
   2.   Photo-cell
   3.   Photo diode
2. What is the maximum number of electrons in shell N of an atom?
   1.   18
   2.   32
   3.   16
3. When an atom loses or gains an electron it is called ?
   1.   a molecule
   2.   an ion
   3.   a current
4. The valence electron is ?
   1.   the electron in outer shell of atom
   2.   the electron in inner shell of atom
   3.   a positive electron
5. Faraday's Law States that?
   1.   the magnitude of the EMF is directly proportional to the magnetic flux
   2.   the magnitude of the EMF is indirectly proportional to the magnetic flux
   3.   the magnitude of the EMF is directly proportional to the rate of change of flux
6. Which of the following is 1 Amp?
   1.   1000 kA
   2.   1000 mA
   3.   1000 μA
7. Ohm's law states that ?
   1.   resistance = current divided by e.m.f
   2.   current = e.m.f. divided by resistance
   3.   e.m.f. = current divided by resistance
8. The SI unit of work is ?
   1.   Joules per metre
   2.   Kilogram metres-force
   3.   Joules per second (Watts)
9. Electromotive force is measured in?
   1.   Watts
   2.   Ohms
   3.   Volts
10. The basis for transformer operation in the use of alternating current is mutual?
    1.   inductance
    2.   capacitance
    3.   reactance
11. The S.I. unit of magnetic flux density is the ?
    1.   Tesla
    2.   Weber
    3.   Henry
12. A shunt is used with?
    1.   a voltmeter
    2.   an ammeter
    3.   an ohmmeter
13. The symbol for flux density is?
    1.   MMF
    2.   H
    3.   B
14. One purpose of the commutator is to ?
    1.   switch the direction of current flow every two cycles
    2.   switch the direction of current flow every cycle
    3.   switch the direction of the current flow every half cycle
15. The rotating part of a motor/generator is called ?
    1.   commutator
    2.   armature
    3.   yoke
16. What is the purpose of the capacitor used in a single phase AC motor ?
    1.   Smoothing
    2.   Provides a high starting torque
    3.   Changing direction of motor
17. In a two-phase induction motor there are ?
    1.   2 poles
    2.   3 poles
    3.   4 poles
18. In a synchronous motor, when the motor is running the slip is?
    1.   5%
    2.   0%
    3.   100%
19. In a 3 phase motor, if 1 phase is lost, the motor ?
    1.   runs at 2 thirds speed
    2.   runs at 1 third speed
    3.   remains at the same speed
20. An AC generator is rated at 30 kVA at 0.8 Power Factor: this means that the maximum continuous output should not exceed?
    1.   30 KW
    2.   24 KW
    3.   37.5 KW
21. Delta wound line current is ?
    1.   root 3 * phase current
    2.   equal to phase current
    3.   less than the phase current
22. Power factor of a generator is ?
    1.   sin ø
    2.   tan ø
    3.   cos ø
23. The 'A' phase of a three phase power system is colour coded?
    1.   blue
    2.   red
    3.   yellow
24. In a 2 phase generator, how far apart are the windings electrically?
    1.   90°
    2.   180°
    3.   45°
25. Band pass filter in a circuit?
    1.   allows frequencies above a cut-off frequency to pass
    2.   allows frequencies below a cut-off frequency to pass
    3.   only allows a narrow band of frequency to pass
26. A capacitor in series and inductor in parallel make what kind of filter?
    1.   Band pass
    2.   High pass
    3.   Low pass
27. Which is a high-pass filter ?
    1.   Π type with series C and L
    2.   L type with series C and shunt L
    3.   L type with series L and shunt C
28. Aircraft autotransformers are of what type?
    1.   Open core
    2.   Twin core
    3.   Laminated core
29. A 3-phase star-delta wound transformer gives?
    1.   30° phase shift
    2.   90° phase shift
    3.   no phase shift
30. An autotransformer windings are?
    1.   wired in parallel
    2.   on separate formers
    3.   connected
31. What causes a transformer to be noisy ?
    1.   High coil resistance
    2.   An air gap in the core
    3.   High core losses
32. Which of the following would be used to calculate transformer turns ratio?
    1.   primary turns ÷ secondary turns
    2.   primary turns × secondary turns
    3.   secondary turns ÷ primary turns
33. Eddy currents in a transformer can be reduced by ?
    1.   laminations
    2.   using a single solid piece of metal
    3.   using a special non metallic material
34. A step up transformer has ?
    1.   three windings
    2.   one winding
    3.   two windings
35. In this circuit applied voltage is ?
    1.   V = IXL
    2.   V = IXC
    3.   V = I/R
36. The Sine wave signals of a circular time base are ?
    1.   phase separated by 90°
    2.   in phase
    3.   phase separated by 180°
37. The controlling wave in a CRT is ?
    1.   sawtooth
    2.   sinusoidal
    3.   square
38. If the frequency is increased in an AC circuit of pure resistance, the effect is?
    1.   increased resistance
    2.   decreased resistance
    3.   nothing
39. The average value of 100 volts peak AC is ?
    1.   141.4 volts
    2.   63.7 volts
    3.   70.7 volts
40. Frequency (Hz) is the number of cycles per ?
    1.   minute
    2.   revolution
    3.   second
41. A parallel circuit at resonance has?
    1.   maximum impedance
    2.   zero impedance
    3.   minimum impedance
42. Prolonged reactive sparking in a DC generator could damage the?
    1.   pole pieces
    2.   commutator
    3.   armature
43. Lines of magnetic flux pass from ?
    1.   South to North
    2.   East to West
    3.   North to South
44. The unit of flux is the ?
    1.   Weber
    2.   Ampere turns
    3.   Ampere turns / metre
45. The lines of magnetic flux from a magnet will?
    1.   attract each other
    2.   repel each other
    3.   have no effect upon each other
46. Ferromagnetic materials can be magnetized ?
    1.   within a band of temperatures
    2.   above a certain temperature
    3.   below a certain temperature
47. One microfarad is?
    1.   1 * 10-6 farads
    2.   1 * 1012 farads
    3.   1 * 10-12 farads
48. A capacitor has Brown, Black and Orange bands. It's value is ?
    1.   10 picofarads
    2.   10 nanofarads
    3.   100 picofarads
49. The charge on a capacitor is expressed as?
    1.   the ratio Q/V
    2.   the product Q * V
    3.   the product C * V
50. One Picofarad is ?
    1.   1 * 1012 farad
    2.   1 * 10-6 farad
    3.   1 * 10-12 farad
51. In a power circuit, the purpose of an inductor is?
    1.   to dampen power surges
    2.   to dampen current surges
    3.   to dampen voltage Surges
52. A thyristor ?
    1.   has a positive temperature coefficient
    2.   if energized on, will switch on a circuit
    3.   if energized on, will switch off a circuit

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