ELECTRODIAGNOSTICS
ELECTRODIAGNOSTICS MCQs
1. The megger is used for the measurement of _________
(A) Insulation resistance (B) Power (C) Flux (D) Voltage
Ans: A
2. In data transmission which of the following system gives maximum probability error ?
(A) PSK (B) FSK (C) ASK (D) DPSK
Ans: C
3. Location of balun in a TV system is between
(A) AGC Stages (B) Feeder and Receiver (C) Antenna and Receiver (D) There is no balun
Ans: B
4. _________is not a binary code
(A) CCITT2 (B) ARQ (C) Boudot (D) Morse
Ans: D
5. The amplifier which has no drift is
(A) Chopper amplifier (B) DC amplifier (C) Single ended amplifier (D) Differential amplifier
Ans: A
6. Another name of Y signal is _________
(A) Chrominance (B) multiplexed (C) Luminance (D) Colour difference
Ans: C
7. Sensitivity factor of strain gauge is of the order of _________
(A) 1 – 1.5 (B) 5 – 10 (C) 2.0 – 3.0 (D) 1.5 – 2.0
Ans: D
8. For a transmitted signal if coherence time of the channel is smaller than the symbol period then it is
(A) Frequency selective fading (B) Slow fading (C) Fast fading (D) Frequency non-selective fading
Ans: C
9. RS 232 is the standard for
(A) Parellel port (B) Serial port (C) Game port (D) Network port
Ans: B
10. NADC is the 2G standard for _________
(A) TDMA (B) CDMA (C) Both (A) and (B) (D) none of these
Ans: A
11. Iron losses in a DC machine are independent of variations in _________
(A) speed (B) load (C) voltage (D) speed and voltage
Ans: B
12. Photoconductive cell consist of thin film of _________
(A) Quartz (B) Barium titanate (C) Lithium sulphate (D) Selenium
Ans: D
13. A transistor has a current gain of 0.99 in CB mode its current gain in CC mode is
(A) 100 (B) 99 (C) 1.01 (D) 0.99
Ans: A
14. ESD cause the damage to which component ?
(A) Monitor (B) Keyboard (C) Power supply (D) Expansion card
Ans: D
15. DECT stands for
(A) Digital Europian Cellular Telex
(B) Digital Europian Cordless Telephone
(C) Digital Europian Cellular Telephone
(D) Digital Emergency Cellular Telephone
Ans: B
16. A microprocessor based system the software used is _________
(A) Firmware (B) Assembly language (C) Machine language (D) Basic interpreter instructions
Ans: B
17. The Optical device used for routing signals from one device to another is_________
(A) Coupler (B) Splitter (C) Optical combiner (D) All of the above
Ans: D
18. The transient response of a system is due to _________
(A) Friction (B) Inertia (C) Stored energy (D) Internal forces
Ans: C
19. The ideal grade of service is _________
(A) 10% (B) 100% (C) 1% (D) 0%
Ans: D
20. In a DC generator the critical resistance refers to the resistance of_________
(A) Field (B) Brushes (C) Armature (D) Load ___________ Ans: A
(A) Insulation resistance (B) Power (C) Flux (D) Voltage
Ans: A
2. In data transmission which of the following system gives maximum probability error ?
(A) PSK (B) FSK (C) ASK (D) DPSK
Ans: C
3. Location of balun in a TV system is between
(A) AGC Stages (B) Feeder and Receiver (C) Antenna and Receiver (D) There is no balun
Ans: B
4. _________is not a binary code
(A) CCITT2 (B) ARQ (C) Boudot (D) Morse
Ans: D
5. The amplifier which has no drift is
(A) Chopper amplifier (B) DC amplifier (C) Single ended amplifier (D) Differential amplifier
Ans: A
6. Another name of Y signal is _________
(A) Chrominance (B) multiplexed (C) Luminance (D) Colour difference
Ans: C
7. Sensitivity factor of strain gauge is of the order of _________
(A) 1 – 1.5 (B) 5 – 10 (C) 2.0 – 3.0 (D) 1.5 – 2.0
Ans: D
8. For a transmitted signal if coherence time of the channel is smaller than the symbol period then it is
(A) Frequency selective fading (B) Slow fading (C) Fast fading (D) Frequency non-selective fading
Ans: C
9. RS 232 is the standard for
(A) Parellel port (B) Serial port (C) Game port (D) Network port
Ans: B
10. NADC is the 2G standard for _________
(A) TDMA (B) CDMA (C) Both (A) and (B) (D) none of these
Ans: A
11. Iron losses in a DC machine are independent of variations in _________
(A) speed (B) load (C) voltage (D) speed and voltage
Ans: B
12. Photoconductive cell consist of thin film of _________
(A) Quartz (B) Barium titanate (C) Lithium sulphate (D) Selenium
Ans: D
13. A transistor has a current gain of 0.99 in CB mode its current gain in CC mode is
(A) 100 (B) 99 (C) 1.01 (D) 0.99
Ans: A
14. ESD cause the damage to which component ?
(A) Monitor (B) Keyboard (C) Power supply (D) Expansion card
Ans: D
15. DECT stands for
(A) Digital Europian Cellular Telex
(B) Digital Europian Cordless Telephone
(C) Digital Europian Cellular Telephone
(D) Digital Emergency Cellular Telephone
Ans: B
16. A microprocessor based system the software used is _________
(A) Firmware (B) Assembly language (C) Machine language (D) Basic interpreter instructions
Ans: B
17. The Optical device used for routing signals from one device to another is_________
(A) Coupler (B) Splitter (C) Optical combiner (D) All of the above
Ans: D
18. The transient response of a system is due to _________
(A) Friction (B) Inertia (C) Stored energy (D) Internal forces
Ans: C
19. The ideal grade of service is _________
(A) 10% (B) 100% (C) 1% (D) 0%
Ans: D
20. In a DC generator the critical resistance refers to the resistance of_________
(A) Field (B) Brushes (C) Armature (D) Load ___________ Ans: A
21. Resistivity of a conductor is the resistance between _______ faces of a cube of that material.
(A) opposite (B) adjacent (C) side to top (D) side to bottom
Ans: A
22. Capacitance between two plates is
(A) C=Q/V (B) C=QV (C) C= V/Q (D) C= V/I
Ans: A
23. Zero error of an instrument is _________
(A) Gross error (B) Random error (C) Indefinite error (D) systematic error
Ans: D
24. Reluctance is the property of a material which opposes the creation of__________ in it.
(A) Current (B) Voltage (C) Magnetic flux (D) Resistance
Ans: C
25. The hall effect voltage of intrinsic silicon is _________
(A) Positive (B) Negative (C) Zero (D) Changed by the application of magnetic field
Ans: B
26. Opto coupler is used for_________
(A) Regulate gate signal (B) Reduce SCR turn - off time (C) Isolate gate circuit from power line (D) Protect IGBT against dv/dt
Ans: C
27. Energy stored in magnetic circuit is equal to _________.
(A) LI (B) LI/2 (C) LI2/2 (D) NI
Ans: C
28. Capacity of a cell is measured in _______
(A) Amp. (B) Wh. (C) Cm3 (D) AH
Ans: D
29. A damping force acts on the moving system when the pointer is _______
(A) At rest (B) Stationary (C) Faulty (D) Moving
Ans: D
30. An ammeter range can be extended by using ________
(A) Inductor (B) Shunt (C) Multiplier (D) Capacitor
Ans: B
31. The main advantage of schottky TTL logic family is its least
(A) power dissipation (B) propagation delay (C) Fan-in (D) Noise immunity
Ans: B
32. When negative feedback is employed _________ reduces
(A) Stability (B) Input impedence (C) Bandwidth (D) Distortion
Ans: D
33. Which one of the following is not a component of PLL ?
(A) Phase detector (B) Frequency Multiplier (C) Loop Filter (D) VCO
Ans: B
34. _______ transducer is used for measuring the magnetic flux density
(A) Hall effect transducer (B) Thermocouple (C) LVDT (D) Strain gauge
Ans: A
35. Resonance frequency is one at which net reactance is _______ and impedance is _______
(A) R and 0 (B) R and XL (C) 0 and R (D) Xc and XL
Ans: C
(A) opposite (B) adjacent (C) side to top (D) side to bottom
Ans: A
22. Capacitance between two plates is
(A) C=Q/V (B) C=QV (C) C= V/Q (D) C= V/I
Ans: A
23. Zero error of an instrument is _________
(A) Gross error (B) Random error (C) Indefinite error (D) systematic error
Ans: D
24. Reluctance is the property of a material which opposes the creation of__________ in it.
(A) Current (B) Voltage (C) Magnetic flux (D) Resistance
Ans: C
25. The hall effect voltage of intrinsic silicon is _________
(A) Positive (B) Negative (C) Zero (D) Changed by the application of magnetic field
Ans: B
26. Opto coupler is used for_________
(A) Regulate gate signal (B) Reduce SCR turn - off time (C) Isolate gate circuit from power line (D) Protect IGBT against dv/dt
Ans: C
27. Energy stored in magnetic circuit is equal to _________.
(A) LI (B) LI/2 (C) LI2/2 (D) NI
Ans: C
28. Capacity of a cell is measured in _______
(A) Amp. (B) Wh. (C) Cm3 (D) AH
Ans: D
29. A damping force acts on the moving system when the pointer is _______
(A) At rest (B) Stationary (C) Faulty (D) Moving
Ans: D
30. An ammeter range can be extended by using ________
(A) Inductor (B) Shunt (C) Multiplier (D) Capacitor
Ans: B
31. The main advantage of schottky TTL logic family is its least
(A) power dissipation (B) propagation delay (C) Fan-in (D) Noise immunity
Ans: B
32. When negative feedback is employed _________ reduces
(A) Stability (B) Input impedence (C) Bandwidth (D) Distortion
Ans: D
33. Which one of the following is not a component of PLL ?
(A) Phase detector (B) Frequency Multiplier (C) Loop Filter (D) VCO
Ans: B
34. _______ transducer is used for measuring the magnetic flux density
(A) Hall effect transducer (B) Thermocouple (C) LVDT (D) Strain gauge
Ans: A
35. Resonance frequency is one at which net reactance is _______ and impedance is _______
(A) R and 0 (B) R and XL (C) 0 and R (D) Xc and XL
Ans: C
36. Laminations reduces _______ loss in an electric machine
(A) Copper loss (B) frictional loss (C) hysteresis loss (D) eddy current loss
Ans: D
37. Lap winding is used for ________ machines.
(A) low current low Voltage (B) high voltage low current (C) high current low voltage (D) high voltage high current
Ans: C
38. Shaft torque of a DC motor is ________ than it's armature torque.
(A) higher (B) equal (C) double (D) less
Ans: D
39. The gain bandwidth product of an amplifier is _________
(A) Constant (B) increase with bandwidth (C) increase with gain (D) none of these
Ans: A
40. Wattmeter reading in an OC test of a transformer gives ________ loss
(A) Copper (B) Core (C) Eddy current (D) Hysteresis
Ans: B
41. The saving in copper with an auto transformer as compared to ordinary transformer is
(A) KWo (B) Wo/K (C) (l – K)Wo (D) (l + K)Wo
Ans: A
42. Intel 8086 microprocessor has _________ line data bus
(A) 16 (B) 8 (C) 32 (D) 12
Ans: A
43. The law defines the polarity of induced emf in a coil is
(A) Faraday’s law (B) Lenz’s law (C) Fleming’s law (D) Ampere’s law
Ans: B
44. Synchronous speed of a 4 pole 50 hertz induction motor is
(A) 1000 rpm (B) 1500 rpm (C) 2000 rpm (D) 3000 rpm
Ans: B
45. In the circle diagram of an induction motor the line joining from the tip of the Isn to Io is
(A) torque line (B) output line (C) power line (D) voltage line
Ans: B
46. The holding current is _________ than the latching current in thyristor
(A) More (B) Less (C) Equal (D) None of the above
Ans: B
47. In a double cage induction motor outer winding has ________ resistance
(A) Low (B) Medium (C) High (D) Zero
Ans: C
48. In an induction motor the torque is _________ to the flux
(A) Directly proportional (B) Equal (C) Not proportional (D) Inversely proportional
Ans: A
49. The frequency of alternating voltage of an alternator is ________
(A) 120 N/P (B) 120 P/N (C) PN/120 (D) N/120P
Ans: C
50. __________type rotors are used for high;speed alternators
(A) Slip ring type (B) Projecting pole type (C) Squirrel cage type (D) Smooth cylindrical type
Ans: D
51. Short pitched windings are used in alternators because
(A) To eliminate harmonics (B) To save copper (C) To reduce the losses (D) All of the above
Ans: D
52. The breakdown mechanism occurs in Zener Diode is_________
(A) Zener breakdown (B) Avalanche breakdown (C) Tunnelling (D) Both (A) & (B)
Ans: D
53. Synchronous reactance of an alternator includes
(A) Leakage reactance and armature reaction reactance
(B) Both resistance and reactance
(C) Capacitance and leakage reactance
(D) Armature reactance and resistance
Ans: A
54. _______ Motor runs at constant speed irrespective of the load.
(A) Induction motor (B) Series motor (C) Synchronous motor (D) Shunt motor
Ans: C
55. _______ lamp has higher luminous efficiency.
(A) Incandescent (B) Fluorescent (C) CFL (D) LED
Ans: D
56. Example for a trivalent impurity is _________
(A) Germanium (B) Silicon (C) Indium (D) Carbon
Ans: C
57. Zener diodes are used for _________
(A) voltage regulation (B) rectification (C) amplification (D) current reduction
Ans: A
58. _________ material can be used as fuse wire
(A) Iron (B) Lead tin alloy (C) Aluminium (D) Nickel chromium alloy
Ans: B
59. Corona is the effect occurring in ________
(A) transformers (B) transmission lines (C) generators (D) motors
Ans: B
60. The wire used for service connection is _________
(A) Weather proof wire (B) lead sheathed wire (C) PVC wire (D) CTS wire
Ans: A
61. An Ideal OP-AMP has _________
(A) Zero gain (B) Infinite gain (C) Infinite output resistance (D) Zero input resistance
Ans: B
62. Which one of the following Bridge is used for the measurement of frequency ?
(A) Wein bridge (B) Wheatstones bridge (C) Maxwell bridge (D) Schering bridge
Ans: A
63. Among the following which instrument is used for the measurement of electrical activity of brain ?
(A) ECG (B) EMG (C) ENG (D) EEG
Ans: D
64.The UPS in which the inverter is ON even the main power is ON is
(A) OFF Line UPS (B) ON Line UPS (C) Electronic generator (D) None of the above
Ans: B
65. Efficiency is maximum in _________ amplifier
(A) Class A (B) Class C (C) Class B (D) None of these
Ans: B
66. In personnel computer the BIOS is stored in
(A) RAM (B) Registers (C) ROM (D) All of the above
Ans: C
67. The electromagnetic modes does not exist in waveguide is
(A) TEM (B) TE11 (C) TE01 (D) TM01
Ans: A
36. Laminations reduces _______ loss in an electric machine
(A) Copper loss (B) frictional loss (C) hysteresis loss (D) eddy current loss
Ans: D
37. Lap winding is used for ________ machines.
(A) low current low Voltage (B) high voltage low current (C) high current low voltage (D) high voltage high current
Ans: C
38. Shaft torque of a DC motor is ________ than it's armature torque.
(A) higher (B) equal (C) double (D) less
Ans: D
39. The gain bandwidth product of an amplifier is _________
(A) Constant (B) increase with bandwidth (C) increase with gain (D) none of these
Ans: A
40. Wattmeter reading in an OC test of a transformer gives ________ loss
(A) Copper (B) Core (C) Eddy current (D) Hysteresis
Ans: B
41. The saving in copper with an auto transformer as compared to ordinary transformer is
(A) KWo (B) Wo/K (C) (l – K)Wo (D) (l + K)Wo
Ans: A
42. Intel 8086 microprocessor has _________ line data bus
(A) 16 (B) 8 (C) 32 (D) 12
Ans: A
43. The law defines the polarity of induced emf in a coil is
(A) Faraday’s law (B) Lenz’s law (C) Fleming’s law (D) Ampere’s law
Ans: B
44. Synchronous speed of a 4 pole 50 hertz induction motor is
(A) 1000 rpm (B) 1500 rpm (C) 2000 rpm (D) 3000 rpm
Ans: B
45. In the circle diagram of an induction motor the line joining from the tip of the Isn to Io is
(A) torque line (B) output line (C) power line (D) voltage line
Ans: B
46. The holding current is _________ than the latching current in thyristor
(A) More (B) Less (C) Equal (D) None of the above
Ans: B
47. In a double cage induction motor outer winding has ________ resistance
(A) Low (B) Medium (C) High (D) Zero
Ans: C
48. In an induction motor the torque is _________ to the flux
(A) Directly proportional (B) Equal (C) Not proportional (D) Inversely proportional
Ans: A
49. The frequency of alternating voltage of an alternator is ________
(A) 120 N/P (B) 120 P/N (C) PN/120 (D) N/120P
Ans: C
50. __________type rotors are used for high;speed alternators
(A) Slip ring type (B) Projecting pole type (C) Squirrel cage type (D) Smooth cylindrical type
Ans: D
51. Short pitched windings are used in alternators because
(A) To eliminate harmonics (B) To save copper (C) To reduce the losses (D) All of the above
Ans: D
52. The breakdown mechanism occurs in Zener Diode is_________
(A) Zener breakdown (B) Avalanche breakdown (C) Tunnelling (D) Both (A) & (B)
Ans: D
53. Synchronous reactance of an alternator includes
(A) Leakage reactance and armature reaction reactance
(B) Both resistance and reactance
(C) Capacitance and leakage reactance
(D) Armature reactance and resistance
Ans: A
54. _______ Motor runs at constant speed irrespective of the load.
(A) Induction motor (B) Series motor (C) Synchronous motor (D) Shunt motor
Ans: C
55. _______ lamp has higher luminous efficiency.
(A) Incandescent (B) Fluorescent (C) CFL (D) LED
Ans: D
56. Example for a trivalent impurity is _________
(A) Germanium (B) Silicon (C) Indium (D) Carbon
Ans: C
57. Zener diodes are used for _________
(A) voltage regulation (B) rectification (C) amplification (D) current reduction
Ans: A
58. _________ material can be used as fuse wire
(A) Iron (B) Lead tin alloy (C) Aluminium (D) Nickel chromium alloy
Ans: B
59. Corona is the effect occurring in ________
(A) transformers (B) transmission lines (C) generators (D) motors
Ans: B
60. The wire used for service connection is _________
(A) Weather proof wire (B) lead sheathed wire (C) PVC wire (D) CTS wire
Ans: A
61. An Ideal OP-AMP has _________
(A) Zero gain (B) Infinite gain (C) Infinite output resistance (D) Zero input resistance
Ans: B
62. Which one of the following Bridge is used for the measurement of frequency ?
(A) Wein bridge (B) Wheatstones bridge (C) Maxwell bridge (D) Schering bridge
Ans: A
63. Among the following which instrument is used for the measurement of electrical activity of brain ?
(A) ECG (B) EMG (C) ENG (D) EEG
Ans: D
64.The UPS in which the inverter is ON even the main power is ON is
(A) OFF Line UPS (B) ON Line UPS (C) Electronic generator (D) None of the above
Ans: B
65. Efficiency is maximum in _________ amplifier
(A) Class A (B) Class C (C) Class B (D) None of these
Ans: B
66. In personnel computer the BIOS is stored in
(A) RAM (B) Registers (C) ROM (D) All of the above
Ans: C
67. The electromagnetic modes does not exist in waveguide is
(A) TEM (B) TE11 (C) TE01 (D) TM01
Ans: A