McqMate
| 1. |
. Which of the following parameters is not a primary parameter? |
| A. | resistance |
| B. | attenuation constant |
| C. | capacitance |
| D. | conductance |
| Answer» B. attenuation constant | |
| 2. |
ohm is |
| A. | 50 |
| B. | 20 |
| C. | 1000 |
| D. | 125 |
| Answer» D. 125 | |
| 3. |
For a matched line, the input impedance will be equal to |
| A. | load impedance |
| B. | characteristic impedance |
| C. | output impedance |
| D. | zero |
| Answer» B. characteristic impedance | |
| 4. |
wave ratio of 2.5 is |
| A. | 20 |
| B. | 125 |
| C. | 200 |
| D. | 75 |
| Answer» B. 125 | |
| 5. |
The average power in an electromagnetic wave is given by |
| A. | propagation constant |
| B. | pointing vector |
| C. | phase constant |
| D. | attenuation constant |
| Answer» B. pointing vector | |
| 6. |
The characteristic impedance of a transmission line is normally chosen to be |
| A. | 50 |
| B. | 75 |
| C. | 50 or 75 |
| D. | 100 |
| Answer» C. 50 or 75 | |
| 7. |
Identify the material which is not present in a transmission line setup. |
| A. | waveguides |
| B. | cavity resonator |
| C. | antenna |
| D. | oscillator |
| Answer» D. oscillator | |
| 8. |
respectively. The standing wave ratio is |
| A. | 2 |
| B. | 3 |
| C. | 1/2 |
| D. | 4 |
| Answer» B. 3 | |
| 9. |
The range of the standing wave ratio is |
| A. | 0 < s < 1 |
| B. | -1 < s < 1 |
| C. | 1 < s < ∞ |
| D. | 0 < s < ∞ |
| Answer» C. 1 < s < ∞ | |
| 10. |
The best stub selection for the transmission line will be |
| A. | series open |
| B. | series short |
| C. | shunt open |
| D. | shunt short |
| Answer» D. shunt short | |
| 11. |
The phenomenon employed in the waveguide operation is |
| A. | reflection |
| B. | refraction |
| C. | total internal reflection |
| D. | adsorption |
| Answer» C. total internal reflection | |
| 12. |
The dominant mode in waveguide is the mode which has |
| A. | highest frequency |
| B. | highest wavelength |
| C. | lowest phase constant |
| D. | highest attenuation |
| Answer» B. highest wavelength | |
| 13. |
The modes are calculated from which parameter? |
| A. | frequency |
| B. | wavelength |
| C. | phase constant |
| D. | v number |
| Answer» D. v number | |
| 14. |
The circular waveguides use which function in the frequency calculation? |
| A. | laplace function |
| B. | schottky function |
| C. | bessel function |
| D. | transfer function |
| Answer» C. bessel function | |
| 15. |
The scattering parameters are used to indicate the |
| A. | permittivity and permeability |
| B. | electric and magnetic field intensities |
| C. | reflection and transmission coefficients |
| D. | frequency and wavelength |
| Answer» C. reflection and transmission coefficients | |
| 16. |
For the matched line, the parameters S12 and S21 are |
| A. | 1 |
| B. | 0 |
| C. | -1 |
| D. | ∞ |
| Answer» B. 0 | |
| 17. |
The waveguides are materials with characteristics of |
| A. | low bulk resistivity |
| B. | high bulk resistivity |
| C. | high conductivity |
| D. | low conductivity |
| Answer» A. low bulk resistivity | |
| 18. |
range of |
| A. | hz |
| B. | khz |
| C. | mhz |
| D. | ghz |
| Answer» D. ghz | |
| 19. |
In rectangular waveguides, the dimensions a and b represent the |
| A. | broad wall dimensions |
| B. | broad wall and side wall dimension respectively |
| C. | side wall and broad wall dimension respectively |
| D. | side wall dimensions |
| Answer» B. broad wall and side wall dimension respectively | |
| 20. |
The cut off frequency for a waveguide to operate is |
| A. | 3 mhz |
| B. | 3 ghz |
| C. | 6 mhz |
| D. | 6 ghz |
| Answer» D. 6 ghz | |
| 21. |
In transverse electric waves, which of the following is true? |
| A. | e is parallel to h |
| B. | e is parallel to wave direction |
| C. | e is transverse to wave direction |
| D. | h is transverse to wave direction |
| Answer» C. e is transverse to wave direction | |
| 22. |
The dominant mode in rectangular waveguide is |
| A. | te01 |
| B. | te10 |
| C. | tm01 |
| D. | tm10 |
| Answer» B. te10 | |
| 23. |
The propagation constant for a lossless transmission line will be |
| A. | real |
| B. | complex |
| C. | real and equal to phase constant |
| D. | complex and equal to phase constant |
| Answer» D. complex and equal to phase constant | |
| 24. |
Which of the following parameter is non zero for a lossless line? |
| A. | attenuation |
| B. | resistance |
| C. | conductance |
| D. | phase constant |
| Answer» D. phase constant | |
| 25. |
The phase and group velocities does not depend on which of the following? |
| A. | frequency |
| B. | wavelength |
| C. | phase constant |
| D. | attenuation constant |
| Answer» D. attenuation constant | |
| 26. |
amplifier. |
| A. | linear beam |
| B. | crossed field |
| C. | parallel field |
| D. | none of the mentioned |
| Answer» A. linear beam | |
| 27. |
reflector electrode after the cavity. |
| A. | backward wave oscillator |
| B. | reflex klystron |
| C. | travelling wave tube |
| D. | magnetrons |
| Answer» B. reflex klystron | |
| 28. |
A major disadvantage of klystron amplifier is: |
| A. | low power gain |
| B. | low bandwidth |
| C. | high source power |
| D. | design complexity |
| Answer» B. low bandwidth | |
| 29. |
The material out of which PIN diode is made is: |
| A. | silicon |
| B. | germanium |
| C. | gaas |
| D. | none of the mentioned |
| Answer» A. silicon | |
| 30. |
GaAs is used in the fabrication of GUNN diodes because: |
| A. | gaas is cost effective |
| B. | it less temperature sensitive |
| C. | it has low conduction band electrons |
| D. | less forbidden energy gap |
| Answer» D. less forbidden energy gap | |
| 31. |
GaAs is used in fabricating Gunn diode. Gunn diode is: |
| A. | bulk device |
| B. | sliced device |
| C. | made of different type of semiconductor layers |
| D. | none of the mentioned |
| Answer» A. bulk device | |
| 32. |
The mode of operation in which the Gunn diode is not stable is: |
| A. | gunn oscillation mode |
| B. | limited space charge accumulation mode |
| C. | stable amplification mode |
| D. | bias circuit oscillation mode |
| Answer» A. gunn oscillation mode | |
| 33. |
an IMPATT diode, it results in: |
| A. | avalanche multiplication |
| B. | break down of depletion region |
| C. | high reverse saturation current |
| D. | none of the mentioned |
| Answer» A. avalanche multiplication | |
| 34. |
maintain at safe limit. |
| A. | average current |
| B. | average voltage |
| C. | average bias voltage |
| D. | average resistance |
| Answer» A. average current | |
| 35. |
Expression for the characteristic impedance of a transmission line(λ/4) used for impedance matching is: |
| A. | z1=√(zₒr)l |
| B. | z1=√(zₒ/r)l |
| C. | z1=√(zₒ+r)l |
| D. | none of the mentioned |
| Answer» A. z1=√(zₒr)l | |
| 36. |
If there is no standing wave on a transmission line, then the value of SWR is: |
| A. | 1 |
| B. | 0 |
| C. | infinity |
| D. | insufficient data |
| Answer» A. 1 | |
| 37. |
When a λ/4 transmission line is used for impedance matching, then which of the following is valid? |
| A. | standing waves are present on the λ/4 transmission line |
| B. | no standing waves on the λ/4 transmission line |
| C. | standing waves are not present both on the feed line and the matching λ/4 line |
| D. | standing waves are present on both the feed line and the matching λ/4 line |
| Answer» A. standing waves are present on the λ/4 transmission line | |
| 38. |
The lowest mode of TE mode propagation in a circular waveguide is: |
| A. | te10 mode |
| B. | te00 mode |
| C. | te01 mode |
| D. | te11 mode |
| Answer» C. te01 mode | |
| 39. |
Which primary parameter is uniformly distributed along the length of the conductor? |
| A. | g |
| B. | c |
| C. | l |
| D. | r |
| Answer» D. r | |
| 40. |
Which of the following parameters does not exist in the transmission line equation? |
| A. | r |
| B. | zo |
| C. | zl |
| D. | propagation constant |
| Answer» A. r | |
| 41. |
Find the characteristic impedance of a quarter wave with input and load impedances given by 50 and 25 respectively. |
| A. | 50 |
| B. | 25 |
| C. | 75 |
| D. | 35.35 |
| Answer» D. 35.35 | |
| 42. |
Calculate the transmission coefficient, when the incident and transmitted amplitudes are 10 and 7 respectively. |
| A. | 17 |
| B. | 3 |
| C. | 10/7 |
| D. | 0.7 |
| Answer» D. 0.7 | |
| 43. |
The reflection coefficient of a transmission line having characteristic and load impedances as 50 and 30 ohm respectively is |
| A. | 1/4 |
| B. | 1/8 |
| C. | 1/2 |
| D. | 3/4 |
| Answer» A. 1/4 | |
| 44. |
The major disadvantage of single stub tuning is: |
| A. | it requires a variable length of line between the load and the stub |
| B. | it involves 2 variable parameters |
| C. | complex calculation |
| D. | none of the mentioned |
| Answer» A. it requires a variable length of line between the load and the stub | |
| 45. |
In a double stub tuner circuit, the load is of _______ length from the first stub. |
| A. | fixed length |
| B. | arbitrary length |
| C. | depends on the load impedance to be matched |
| D. | depends on the characteristic impedance of the transmission line |
| Answer» B. arbitrary length | |
| 46. |
The major advantage of double stub tuning is: |
| A. | it uses 2 tuning stubs in fixed positions |
| B. | it involves 2 stubs |
| C. | length of the stub is variable |
| D. | none of the mentioned |
| Answer» A. it uses 2 tuning stubs in fixed positions | |
| 47. |
The modes of propagation supported by a rectangular wave guide is: |
| A. | tm, tem, te modes |
| B. | tm, te |
| C. | tm, tem |
| D. | te, tem |
| Answer» B. tm, te | |
| 48. |
Dominant mode is defined as: |
| A. | mode with the lowest cut off frequency |
| B. | mode with the highest cut off frequency |
| C. | any tem mode is called a dominant mode |
| D. | none of the mentioned |
| Answer» A. mode with the lowest cut off frequency | |
| 49. |
The product of the phase and the group velocities is given by the |
| A. | speed of light |
| B. | speed of light/2 |
| C. | 2 x speed of light |
| D. | (speed of light)/4 |
| Answer» D. (speed of light)/4 | |
| 50. |
For TE1ₒ mode, if the waveguide is filled with air and the broader dimension of the waveguide is 2 cm, then the cutoff frequency is: |
| A. | 5 mhz |
| B. | 7.5 mhz |
| C. | 7.5 ghz |
| D. | 5 ghz |
| Answer» C. 7.5 ghz | |
| 51. |
For dominant mode propagation in TE mode, if the rectangular waveguide has a broader dimension of 31.14 mm , then the cutoff wave number: |
| A. | 100 |
| B. | 500 |
| C. | 50 |
| D. | 1000 |
| Answer» A. 100 | |
| 52. |
The klystron tube used in a klystron amplifier is a _________ type beam amplifier. |
| A. | linear beam |
| B. | crossed field |
| C. | parallel field |
| D. | none of the mentioned |
| Answer» A. linear beam | |
| 53. |
A PIN diode consists of ______number of semiconductor layers. |
| A. | three |
| B. | two |
| C. | four |
| D. | one |
| Answer» A. three | |
| 54. |
The resistance of the PIN diode with positive bias voltage: |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | insufficient data |
| Answer» B. decreases | |
| 55. |
Microstrip line can support a pure TEM wave. |
| A. | true |
| B. | false |
| C. | microstrip supports only tm mode |
| D. | microstrip supports only te mode |
| Answer» B. false | |
| 56. |
The effective dielectric constant ∈r for a microstrip line: |
| A. | varies with frequency |
| B. | independent of frequency |
| C. | it is a constant for a certain material |
| D. | depends on the material used to make microstrip |
| Answer» B. independent of frequency | |
| 57. |
The arcs of circles on smith chart represent |
| A. | normalised resistance or conductance |
| B. | different values of swr |
| C. | normalised reactance or susceptance |
| D. | none of the above |
| Answer» C. normalised reactance or susceptance | |
| 58. |
The characteristic impedance of a transmission line is |
| A. | directly proportional to its length |
| B. | inversely proportional to its length |
| C. | independent of its length |
| D. | none of the above |
| Answer» C. independent of its length | |
| 59. |
Standing wave ratio (SWR) equal to unity implies that |
| A. | the transmission line is open circuited |
| B. | the transmission line is short circuited |
| C. | the transmission line\s characteristic impedance equals load impedance |
| D. | none of the above |
| Answer» C. the transmission line\s characteristic impedance equals load impedance | |
| 60. |
), The normalised load impedance is |
| A. | (1 + j 2) |
| B. | (2500 + j 5000) |
| C. | (0.5 +j) |
| D. | none of the above |
| Answer» A. (1 + j 2) | |
| 61. |
V and a conduction current of 1.2A is |
| A. | 25.2 |
| B. | 22.8 |
| C. | 28.8 |
| D. | 20 |
| Answer» D. 20 | |
| 62. |
and 9 respectively is |
| A. | 25 |
| B. | 1.33 |
| C. | 7 |
| D. | 0.75 |
| Answer» B. 1.33 | |
| 63. |
Input impedance of a shorted lossless line of length π/4 is |
| A. | zero |
| B. | infinity |
| C. | zo |
| D. | none of the above |
| Answer» C. zo | |
| 64. |
V. The SWR is |
| A. | 0.67 |
| B. | 1.2 |
| C. | 1 |
| D. | 1.5 |
| Answer» D. 1.5 | |
| 65. |
The reflection coefficient on a transmission line is 1/3, what is the SWR |
| A. | 0 |
| B. | 3 |
| C. | 2 |
| D. | 4 |
| Answer» C. 2 | |
| 66. |
pF/m and an inductance of 75 nH/m |
| A. | 5 ohm |
| B. | 50 ohm |
| C. | 500 ohm |
| D. | 5000 ohm |
| Answer» B. 50 ohm | |
| 67. |
The wavelength of a line with a phase constant of 3.14 units is |
| A. | 2 |
| B. | 1 |
| C. | 0.5 |
| D. | 3.14 |
| Answer» A. 2 | |
| 68. |
The dominant mode for rectangular waveguide is |
| A. | te11 |
| B. | tm11 |
| C. | te10 |
| D. | tm10 |
| Answer» C. te10 | |
| 69. |
Following waveguide component not easily adjustable for tuning |
| A. | stub |
| B. | iris |
| C. | screw |
| D. | plunger |
| Answer» B. iris | |
| 70. |
What is the wavelength of a wave in a waveguide? |
| A. | greater than in free space |
| B. | depends only on the waveguide dimensions and the free-space wavelength |
| C. | inversely proportional to the phase velocity |
| D. | inversely proportional to the group velocity |
| Answer» A. greater than in free space | |
| 71. |
What is the cut-off frequency of a waveguide? |
| A. | the highest frequency the waveguide operates |
| B. | the lowest frequency the waveguide operates |
| C. | the same as the operating frequency |
| D. | the only frequency the waveguide operates |
| Answer» B. the lowest frequency the waveguide operates | |
| 72. |
For reduction in cross sectional dimension, waveguide to use is |
| A. | ridged |
| B. | circular |
| C. | rectangular |
| D. | flexible |
| Answer» A. ridged | |
| 73. |
Out of following list, is not directional coupler |
| A. | bathe hole |
| B. | two hole |
| C. | rate race |
| D. | magic hole |
| Answer» D. magic hole | |
| 74. |
The condition which will satisfy the dimensions of the waveguide is |
| A. | a = b |
| B. | a>b |
| C. | a<b |
| D. | ab=0 |
| Answer» B. a>b | |
| 75. |
Materials generally preferred for wave guides are |
| A. | brass and aluminium |
| B. | cast iron and steel |
| C. | non-metallic solids including plastics |
| D. | all of the above |
| Answer» A. brass and aluminium | |
| 76. |
cm and b = 1.5 cm with μ = 1 and ε = 2.25 is |
| A. | 377 ohm |
| B. | 327 ohm |
| C. | 227 ohm |
| D. | 127 ohm |
| Answer» C. 227 ohm | |
| 77. |
75GHz? |
| A. | 9.2 cm |
| B. | 3.2 cm |
| C. | 0.6 m |
| D. | 12 cm |
| Answer» A. 9.2 cm | |
| 78. |
5 cm and 1 cm respectively is |
| A. | 4.5 ghz |
| B. | 5 ghz |
| C. | 5.5 ghz |
| D. | 6 ghz |
| Answer» D. 6 ghz | |
| 79. |
5 GHz is |
| A. | 1 cm |
| B. | 2 cm |
| C. | 3 cm |
| D. | 4 cm |
| Answer» B. 2 cm | |
| 80. |
A major disadvantage of klystron amplifier is |
| A. | low power gain |
| B. | low bandwidth |
| C. | high source power |
| D. | design complexity |
| Answer» B. low bandwidth | |
| 81. |
A PIN diode consists of........number of semiconductor layers. |
| A. | three |
| B. | two |
| C. | four |
| D. | one |
| Answer» A. three | |
| 82. |
The resistance of the PIN diode with positive bias voltage |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | insufficient data |
| Answer» B. decreases | |
| 83. |
GaAs is used in the fabrication of GUNN diodes because |
| A. | gaas is cost effective |
| B. | it less temperature sensitive |
| C. | it has low conduction band electrons |
| D. | less forbidden energy gap |
| Answer» D. less forbidden energy gap | |
| 84. |
The number of modes of operation for n type GaAs Gunn diode is |
| A. | two |
| B. | three |
| C. | four |
| D. | five |
| Answer» C. four | |
| 85. |
The number of semiconductor layers in IMPATT diode is: |
| A. | two |
| B. | three |
| C. | four |
| D. | none of the mentioned |
| Answer» C. four | |
| 86. |
The cavity resonator |
| A. | is equivalent to an lc resonant circuit |
| B. | in a reflect klystron has its output taken from the reflector plate |
| C. | produces a frequency which is independent of the cavity size. |
| D. | has a low q factor for narrow operation. |
| Answer» A. is equivalent to an lc resonant circuit | |
| 87. |
A traveling-wave tube (TWT) amplifies by virtue of |
| A. | the absorption of energy by the signal from an electron stream |
| B. | the effect of an external magnetic field |
| C. | the energy contained the cavity resonators |
| D. | the energy liberated form the collector |
| Answer» A. the absorption of energy by the signal from an electron stream | |
| 88. |
Which of the following is used as a high power microwave oscillator? |
| A. | thyratron |
| B. | magnetron |
| C. | klystron |
| D. | reflex-klystron |
| Answer» B. magnetron | |
| 89. |
The characterstic impedance of a transmission line depends upon |
| A. | shape of the conductor |
| B. | surface treatment of the conductor |
| C. | conductivity of the material |
| D. | geometrical configuration of conductors |
| Answer» D. geometrical configuration of conductors | |
| 90. |
In order to reduce skin effect at ultra high frequencies, |
| A. | conductors are painted |
| B. | conductors are anodized |
| C. | copper rodes with silver plating are used |
| D. | copper lubes with silver plating are used |
| Answer» D. copper lubes with silver plating are used | |
| 91. |
Which of the following are constants of transmission lines |
| A. | resistance |
| B. | inductance |
| C. | capacitance |
| D. | all of the above |
| Answer» D. all of the above | |
| 92. |
Indicate the false statement. The SWR on a transmission line is infinity; the line is
|
| A. | a short circuit |
| B. | an open circuit |
| C. | a complex impedance |
| D. | pure reactance |
| Answer» C. a complex impedance | |
| 93. |
Major advantage of a quarter wave transformer is |
| A. | proper matching |
| B. | high gain |
| C. | broader band width |
| D. | none of the above |
| Answer» C. broader band width | |
| 94. |
The reactances associated with the transmission line due to discontinuities: |
| A. | can be ignored |
| B. | have to be matched |
| C. | discontinuities do no exist |
| D. | none of the above |
| Answer» C. discontinuities do no exist | |
| 95. |
The wave impedance of air for a wave propagating in it is |
| A. | 377 Ω |
| B. | 345 Ω |
| C. | insufficient data |
| D. | none of the above |
| Answer» A. 377 Ω | |
| 96. |
A loss less line of characteristic impedance Z0 is terminated in pure reactance of -
|
| A. | 10 |
| B. | 2 |
| C. | 1 |
| D. | infinity |
| Answer» D. infinity | |
| 97. |
A rectangular air – filled waveguide has a cross section of 4 × 10 The
|
| A. | 1.5 ghz |
| B. | 2.5 ghz |
| C. | 2.0 ghz |
| D. | 3.0 ghz |
| Answer» A. 1.5 ghz | |
| 98. |
Indicate which one of the following modes do not exist in a rectangularresonant
|
| A. | te110 |
| B. | tm110 |
| C. | te011 |
| D. | mt111 |
| Answer» A. te110 | |
| 99. |
The phase velocity of waves propagation in hollow metal waveguide is |
| A. | greater than velocity of light in free space |
| B. | less than velocity of light in free space |
| C. | equal to velocity of light in free space |
| D. | equal to group velocity |
| Answer» C. equal to velocity of light in free space | |
| 100. |
The dominant mode in a rectangular waveguide is TE10 because this mode has |
| A. | no attenuation |
| B. | no cut off |
| C. | no magnetic field component |
| D. | the highest cut off wavelength |
| Answer» D. the highest cut off wavelength | |
Done Reading?