MCQOPTIONS
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MCQOPTIONS
This section includes 247 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
Indicate which one of the following modes do not exist in a rectangularresonantcavity |
| A. | te110 |
| B. | tm110 |
| C. | te011 |
| D. | mt111 |
| Answer» B. tm110 | |
| 52. |
Calculate the transmission coefficient, when the incident and transmitted amplitudes are10 and 7 respectively. |
| A. | 17 |
| B. | 3 |
| C. | 10/7 |
| D. | 0.7 |
| Answer» E. | |
| 53. |
Find the characteristic impedance of a quarter wave with input and load impedances given by50 and 25 respectively. |
| A. | 50 |
| B. | 25 |
| C. | 75 |
| D. | 35.35 |
| Answer» E. | |
| 54. |
Propagation constant γ is given by: |
| A. | α+jβ |
| B. | α-jβ |
| C. | α/jβ |
| D. | α.jβ |
| Answer» B. α-jβ | |
| 55. |
Indicate the false statement. The SWR on a transmission line is infinity; the line isterminated in |
| A. | a short circuit |
| B. | an open circuit |
| C. | a complex impedance |
| D. | pure reactance |
| Answer» D. pure reactance | |
| 56. |
If a transmission line of a characteristics impedance 50 Ω is terminated with a loadimpedance of 100 Ω, then the reflection co efficient is: |
| A. | 0.3334 |
| B. | 0.6667 |
| C. | 1.6 |
| D. | 1.333 |
| Answer» B. 0.6667 | |
| 57. |
Maxwell’s equation for electromagnetic waves in a waveguide is: |
| A. | ∇×e = -jωµ(vector h) |
| B. | ∇×e =-jωμ(vector e) |
| C. | ∇×h=-jωμ(vector h) |
| D. | ∇×h=jωμ(vector h) |
| Answer» B. ∇×e =-jωμ(vector e) | |
| 58. |
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» B. z1=√(zₒ/r)l | |
| 59. |
If a device is passive and contains no anisotropic elements, then the deviceis_______ network. |
| A. | reciprocal |
| B. | non reciprocal |
| C. | lossless |
| D. | lossy |
| Answer» B. non reciprocal | |
| 60. |
ency of 30GHz is (free space impedance 0 =377 Ω) |
| A. | 308 Ω |
| B. | 400 Ω |
| C. | 355 Ω |
| D. | 461 Ω |
| Answer» C. 355 Ω | |
| 61. |
When the electric field applied to GaAs specimen is less than the threshold electricfield, the current in the material: |
| A. | increases linearly |
| B. | decreases linearly |
| C. | increases exponentially |
| D. | decreases exponentially |
| Answer» B. decreases linearly | |
| 62. |
If a transmission line of characteristic impedance 50 Ω is terminated with a loadimpedance of 150 Ω , then VSWR is: |
| A. | 0.75 |
| B. | 0.5 |
| C. | 2 |
| D. | none of the mentioned |
| Answer» B. 0.5 | |
| 63. |
The junction resistance and capacitance of the intrinsic region in a PIN diode areconnected______ in the equivalent circuit of PIN diode. |
| A. | series |
| B. | parallel |
| C. | connected across package capacitance |
| D. | none of the mentioned |
| Answer» C. connected across package capacitance | |
| 64. |
Power dividers and couplers are ______ microwave components used for powerdivision or power combining. |
| A. | passive |
| B. | active |
| C. | linear |
| D. | non linear |
| Answer» B. active | |
| 65. |
The radar in which both transmission and reception is done using the sameantenna are called: |
| A. | monostatic |
| B. | bistatic |
| C. | dipole radar |
| D. | monopole radar |
| Answer» B. bistatic | |
| 66. |
_________ and __________ contribute to the impedance of a transmission line in thelumped element representation. |
| A. | resistor, inductor |
| B. | resistor, capacitor |
| C. | capacitor, inductor |
| D. | transistor, capacitor |
| Answer» B. resistor, capacitor | |
| 67. |
Processing in MMICs is done by __________ |
| A. | ion implantation |
| B. | net list generation |
| C. | floor planning |
| D. | none of the mentioned |
| Answer» B. net list generation | |
| 68. |
For the capacitors used in MMICs, the insulating dielectric films used are: |
| A. | air |
| B. | sio |
| C. | titanium |
| D. | gaas |
| Answer» C. titanium | |
| 69. |
The substrate of an MMIC must be a _____________ to accommodate the fabrication of all the type of devices. |
| A. | semiconductor |
| B. | insulator |
| C. | partial conductors |
| D. | metals operable at high frequencies |
| Answer» B. insulator | |
| 70. |
The maximum theoretical output circuit efficiency of a double resonator klystron amplifier is |
| A. | 25% |
| B. | 50% |
| C. | 58% |
| D. | 85% |
| Answer» D. 85% | |
| 71. |
Which of the following is not possible in a circular wave guide ? |
| A. | te10 |
| B. | te01 |
| C. | te11 |
| D. | te12 |
| Answer» B. te01 | |
| 72. |
A cavity resonator can be represented by |
| A. | an lc circuit |
| B. | an lcr circuit |
| C. | a lossy inductor |
| D. | a lossy capacitor |
| Answer» B. an lcr circuit | |
| 73. |
Ionospheric preparation is not possible for microwaves because |
| A. | microwaves will be fully absorbed by the ionospheric layers |
| B. | there will be an abrupt scattering in all directions |
| C. | microwave will penetrate through the ionospheric layers |
| D. | there will be dispersion of microwave energy |
| Answer» D. there will be dispersion of microwave energy | |
| 74. |
When the electric field applied to GaAs specimen is less than the threshold electric field, the current in the material: |
| A. | increases linearly |
| B. | decreases linearly |
| C. | increases exponentially |
| D. | decreases exponentially |
| Answer» B. decreases linearly | |
| 75. |
Which of the following can be used for amplification of microwave energy? |
| A. | magnetron |
| B. | reflex klystron |
| C. | traveling wave tube |
| D. | gunn diode |
| Answer» D. gunn diode | |
| 76. |
Klystrons operates on the principal of |
| A. | amplitude modulation |
| B. | frequency modulation |
| C. | pulse modulation |
| D. | velocity modulation |
| Answer» E. | |
| 77. |
________ is a single cavity klystron tube that operates as on oscillator by using a reflector electrode after the cavity. |
| A. | backward wave oscillator |
| B. | reflex klystron |
| C. | travelling wave tube |
| D. | magnetrons |
| Answer» C. travelling wave tube | |
| 78. |
When a reverse bias voltage exceeding the breakdown voltage is applied to an IMPATT diode, it results in: |
| A. | break down of depletion region |
| B. | avalanche multiplication |
| C. | high reverse saturation current |
| D. | none of the mentioned |
| Answer» C. high reverse saturation current | |
| 79. |
The width of depletion region of a varactor diode ________with increase in reverse bias voltage. |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | none of the mentioned |
| Answer» B. decreases | |
| 80. |
The junction resistance and capacitance of the intrinsic region in a PIN diode are connected______ in the equivalent circuit of PIN diode. |
| A. | series |
| B. | parallel |
| C. | connected across package capacitance |
| D. | none of the mentioned |
| Answer» C. connected across package capacitance | |
| 81. |
If a microwave network is lossless, then S matrix of the microwave network is: |
| A. | zero matrix |
| B. | symmetric |
| C. | identity matrix |
| D. | unitary |
| Answer» E. | |
| 82. |
If a device is passive and contains no anisotropic elements, then the device is_______ network. |
| A. | reciprocal |
| B. | non reciprocal |
| C. | lossless |
| D. | lossy |
| Answer» B. non reciprocal | |
| 83. |
T- junction is an example for: |
| A. | 2 port network |
| B. | 3 port network |
| C. | 4 port network |
| D. | none of the mentioned |
| Answer» C. 4 port network | |
| 84. |
Power dividers and couplers are ______ microwave components used for power division or power combining. |
| A. | passive |
| B. | active |
| C. | linear |
| D. | non linear |
| Answer» B. active | |
| 85. |
The device commonly used in microwave ovens is the: |
| A. | twt |
| B. | klystron |
| C. | magnetron |
| D. | yig |
| Answer» D. yig | |
| 86. |
A “circulator†is a device that: |
| A. | rotates signal polarity in a waveguide |
| B. | allows a signal to pass in one direction only |
| C. | separates signals among various ports |
| D. | prevents microwaves from being “trapped†in a waveguide |
| Answer» D. prevents microwaves from being “trapped†in a waveguide | |
| 87. |
Directional coupler for waveguide are characterized by |
| A. | insertion loss |
| B. | coupling specification |
| C. | directivity |
| D. | all of the above |
| Answer» E. | |
| 88. |
Ferrite isolators are ____ port microwave devices. |
| A. | two |
| B. | three |
| C. | four |
| D. | none of the mentioned |
| Answer» B. three | |
| 89. |
S parameters are expressed as a ratio of: |
| A. | voltage and current |
| B. | impedance at different ports |
| C. | indecent and the reflected voltage waves |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 90. |
TEâ‚’â‚’ mode for a rectangular waveguide: |
| A. | exists |
| B. | exists but defined only under special cases |
| C. | does not exist |
| D. | cannot be determined |
| Answer» D. cannot be determined | |
| 91. |
In TM mode, if the direction of wave propagation is in ‘z’ direction, then: |
| A. | hz=0 |
| B. | ez=0 |
| C. | ey=0 |
| D. | hy=0 |
| Answer» B. ez=0 | |
| 92. |
The modes of wave propagation that a rectangular waveguide can support are: |
| A. | tem, te, modes |
| B. | tem,tm, te modes |
| C. | tem, tm modes |
| D. | te,tm modes |
| Answer» E. | |
| 93. |
Maxwell’s equation for electromagnetic waves in a waveguide is: |
| A. | ∇×e = -jωµ(vector h) |
| B. | ∇×e =-jωμ(vector e) |
| C. | ∇×h=-jωμ(vector h) |
| D. | ∇×h=jωμ(vector h) |
| Answer» B. ∇×e =-jωμ(vector e) | |
| 94. |
For co-axial lines and waveguides, ________ is more preferred. |
| A. | open circuited stub |
| B. | short circuited stub |
| C. | slotted section |
| D. | co-axial lines cannot be impedance matched |
| Answer» C. slotted section | |
| 95. |
In shunt stub matching, the key parameter used for matching is: |
| A. | admittance of the line at a point |
| B. | admittance of the load |
| C. | impedance of the stub |
| D. | impedance of the load |
| Answer» B. admittance of the load | |
| 96. |
Shunt stubs are preferred for: |
| A. | strip and microstrip lines |
| B. | coplanar waveguides |
| C. | circular waveguide |
| D. | circulators |
| Answer» B. coplanar waveguides | |
| 97. |
The major advantage of single stub tuning over other impedance matching techniques is: |
| A. | lumped elements are avoided |
| B. | it can be fabricated as a part of transmission line media |
| C. | it involves two adjustable parameters |
| D. | all of the mentioned |
| Answer» E. | |
| 98. |
Characteristic impedance of a transmission line is: |
| A. | impedance z of a transmission line |
| B. | impedance which is a constant at any point on the transmission line |
| C. | reciprocal of admittance of a transmission line |
| D. | none of the mentioned |
| Answer» C. reciprocal of admittance of a transmission line | |
| 99. |
Transmission line is a _________ parameter network. |
| A. | lumped |
| B. | distributed |
| C. | active |
| D. | none of the mentioned |
| Answer» C. active | |
| 100. |
_________ and __________ contribute to the impedance of a transmission line in the lumped element representation. |
| A. | resistor, inductor |
| B. | resistor, capacitor |
| C. | capacitor, inductor |
| D. | transistor, capacitor |
| Answer» B. resistor, capacitor | |