MCQOPTIONS
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MCQOPTIONS
This section includes 217 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 151. |
Lens antennas are classified into two types. One being fast antenna, the other one is: |
| A. | slow antenna |
| B. | delay antenna |
| C. | dynamic antenna |
| D. | none of the mentioned |
| Answer» C. dynamic antenna | |
| 152. |
             antennas have gain less than reflector antennas but have more lenient tolerance on surfaces. |
| A. | helical antennas |
| B. | lens antennas |
| C. | array antennas |
| D. | slot antennas |
| Answer» C. array antennas | |
| 153. |
The pattern of the reflector in a reflector antenna is called: |
| A. | primary pattern |
| B. | secondary pattern |
| C. | reflector pattern |
| D. | none of the mentioned |
| Answer» C. reflector pattern | |
| 154. |
Reflector antennas are widely used to modify radiation patterns of radiating elements. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 155. |
Antenna that does not belong to the horn antenna family among the following are: |
| A. | pyramidal horn |
| B. | conical horn |
| C. | bi-conical horn |
| D. | none of the mentioned |
| Answer» E. | |
| 156. |
Based on the size of the loops, loop antennas are classified as small and large loops. This is the only classification of loop antenna. |
| A. | true |
| B. | false |
| Answer» C. | |
| 157. |
The antenna in which location of the feed determines the direction of the lobe are: |
| A. | wire antenna |
| B. | loop antenna |
| C. | helical antenna |
| D. | horn antenna |
| Answer» B. loop antenna | |
| 158. |
The members of the antenna family which are made of wires of certain value in terms of operating wavelength are called: |
| A. | loop antennas |
| B. | wire antennas |
| C. | dipole antenna |
| D. | slot antennas |
| Answer» D. slot antennas | |
| 159. |
Which of the following antennas produce a vertical radiation pattern? |
| A. | dipole antenna |
| B. | yagi antenna |
| C. | marconi antenna |
| D. | hertz antenna |
| Answer» D. hertz antenna | |
| 160. |
What is the impedance of the folded dipole antenna? |
| A. | 50Ω |
| B. | 100Ω |
| C. | 300Ω |
| D. | 20Ω |
| Answer» D. 20Ω | |
| 161. |
What is the radiation pattern of an isotropic radiator? |
| A. | doughnut |
| B. | sphere |
| C. | hemisphere |
| D. | circular |
| Answer» C. hemisphere | |
| 162. |
What is the power radiated by the antenna with gain called as? |
| A. | critical power |
| B. | transverse power |
| C. | effective radiated power |
| D. | transmitted power |
| Answer» D. transmitted power | |
| 163. |
What does the beam width of an antenna tell us? |
| A. | signal strength |
| B. | signal power |
| C. | directivity |
| D. | degradation |
| Answer» D. degradation | |
| 164. |
What is the beam width for a half wave dipole antenna? |
| A. | 90° |
| B. | 180° |
| C. | 50° |
| D. | 250° |
| Answer» B. 180° | |
| 165. |
The radiation pattern of a half-wave dipole has the shape of a |
| A. | doughnut |
| B. | sphere |
| C. | hemisphere |
| D. | circular |
| Answer» B. sphere | |
| 166. |
The type of dipole antenna that has a higher band width is called as? |
| A. | conical antenna |
| B. | yagi antenna |
| C. | helical antenna |
| D. | marconi antenna |
| Answer» B. yagi antenna | |
| 167. |
What happens when the radiation resistance of the antenna matches the characteristic impedance of the transmission line? |
| A. | no transmission occurs |
| B. | no reception occurs |
| C. | swr is maximum |
| D. | swr is minimum |
| Answer» E. | |
| 168. |
The impedance at the center of the antenna is known as? |
| A. | characteristic impedance |
| B. | radiation resistance |
| C. | transmission impedance |
| D. | recovery resistance |
| Answer» C. transmission impedance | |
| 169. |
A dipole antenna is also called as? |
| A. | marconi antenna |
| B. | yagi antenna |
| C. | bidirectional antenna |
| D. | hertz antenna |
| Answer» E. | |
| 170. |
Effective radiated power of an isotropic radiator can be given as a product of |
| A. | radiated power and received power |
| B. | effective area and physical area |
| C. | transmitted power and transmitting gain |
| D. | receiving power and receiving gain |
| Answer» D. receiving power and receiving gain | |
| 171. |
Antenna’s efficiency is given by the ratio of |
| A. | effective aperture to physical aperture |
| B. | physical aperture to effective aperture |
| C. | signal power to noise power |
| D. | losses |
| Answer» B. physical aperture to effective aperture | |
| 172. |
Space loss occurs due to a decrease in |
| A. | electric field strength |
| B. | efficiency |
| C. | phase |
| D. | signal power |
| Answer» B. efficiency | |
| 173. |
Mechanism contributing to a reduction in efficiency is called as |
| A. | amplitude tapering |
| B. | blockage |
| C. | edge diffraction |
| D. | all of the mentioned |
| Answer» E. | |
| 174. |
Antennas are used |
| A. | as transducer |
| B. | to focus |
| C. | as transducer & to focus |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 175. |
Which factor adds phase noise to the signal? |
| A. | jitter |
| B. | phase fluctuations |
| C. | jitter & phase fluctuations |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 176. |
Which is the primary cost for degradation of error performance? |
| A. | loss in signal to noise ratio |
| B. | signal distortion |
| C. | signal distortion & loss in signal to noise ratio |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 177. |
Link budget consists of calculation of |
| A. | useful signal power |
| B. | interfering noise power |
| C. | useful signal & interfering noise power |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 178. |
If the reflection coefficient of a transmission line is 0.4, then the standing wave ratio is: |
| A. | 1.3333 |
| B. | 2.3333 |
| C. | 0.4 |
| D. | 0.6 |
| Answer» C. 0.4 | |
| 179. |
If the normalized load impedance of a transmission line is 2, then the reflection co- efficient is: |
| A. | 0.33334 |
| B. | 1.33334 |
| C. | 1 |
| Answer» B. 1.33334 | |
| 180. |
In the expression for phase of the reflection coefficient, Lmin stands for : |
| A. | distance between load and first voltage minimum |
| B. | distance between load and first voltage maximum |
| C. | distance between consecutive minimas |
| D. | distance between a minima and immediate maxima |
| Answer» B. distance between load and first voltage maximum | |
| 181. |
If the standing wave ratio for a transmission line is 1.4, then the reflection coefficient for the line is: |
| A. | 0.16667 |
| B. | 1.6667 |
| C. | 0.01667 |
| D. | 0.96 |
| Answer» B. 1.6667 | |
| 182. |
A modern device that replaces a slotted line is: |
| A. | digital cro |
| B. | generators |
| C. | network analyzers |
| D. | computers |
| Answer» D. computers | |
| 183. |
Slotted line is a transmission line configuration that allows the sampling of: |
| A. | electric field amplitude of a standing wave on a terminated line |
| B. | magnetic field amplitude of a standing wave on a terminated line |
| C. | voltage used for excitation |
| D. | current that is generated by the source |
| Answer» B. magnetic field amplitude of a standing wave on a terminated line | |
| 184. |
                   has a constant power spectral density. |
| A. | white noise |
| B. | gaussian noise |
| C. | thermal noise |
| D. | shot noise |
| Answer» B. gaussian noise | |
| 185. |
A resistor is operated at a temperature of 300 K, with a system bandwidth of 1 MHz then the noise power produced by the resistor is: |
| A. | 3.13×10-23 watts |
| B. | 4.14×10-15 watts |
| C. | 6.14×10-15 watts |
| D. | none of the mentioned |
| Answer» C. 6.14×10-15 watts | |
| 186. |
Low is the G/T ratio of an antenna, higher is its efficiency. |
| A. | true |
| B. | false |
| Answer» C. | |
| 187. |
The noise temperature of an antenna is given by the expression: |
| A. | radtb + (1-rad) tp |
| B. | (1-rad) tp |
| C. | radtb |
| D. | none of the mentioned |
| Answer» B. (1-rad) tp | |
| 188. |
With an increase in operating frequency, the background noise temperature: |
| A. | increases |
| B. | decreases |
| C. | remains constant |
| D. | remains unaffected |
| Answer» B. decreases | |
| 189. |
Gain of an antenna is always greater than the directivity of the antenna. |
| A. | true |
| B. | false |
| Answer» C. | |
| 190. |
A rectangular horn antenna has an aperture area of 3λ × 2λ. Then the maximum directivity that can be achieved by this rectangular horn antenna is: |
| A. | 24 db |
| B. | 4 db |
| C. | 19 db |
| D. | insufficient data |
| Answer» D. insufficient data | |
| 191. |
A rectangular horn antenna has an aperture area of 3λ × 2λ. If the aperture efficiency of an antenna is 90%, then the directivity of the antenna is: |
| A. | 19 db |
| B. | 17.1 db |
| C. | 13 db |
| D. | 21.1 db |
| Answer» C. 13 db | |
| 192. |
If the power input to an antenna is 100 mW and if the radiated power is measured to be 90 mW, then the efficiency of the antenna is: |
| A. | 75 % |
| B. | 80 % |
| C. | 90 % |
| D. | insufficient data |
| Answer» D. insufficient data | |
| 193. |
If an antenna has a directivity of 16 and radiation efficiency of 0.9, then the gain of the antenna is: |
| A. | 16.2 |
| B. | 14.8 |
| C. | 12.5 |
| D. | 19.3 |
| Answer» B. 14.8 | |
| 194. |
If the beam width of an antenna in two orthogonal planes are 300 and 600. Then the directivity of the antenna is: |
| A. | 24 |
| B. | 18 |
| C. | 36 |
| D. | 12 |
| Answer» C. 36 | |
| 195. |
                   of an antenna is a plot of the magnitude of the far field strength versus position around the antenna. |
| A. | radiation pattern |
| B. | directivity |
| C. | beam width |
| D. | none of the mentioned |
| Answer» B. directivity | |
| 196. |
Beamwidth and directivity are both measures of the focusing ability of an antenna. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 197. |
Antennas having a constant pattern in the azimuthal plane are called |
| A. | high gain antenna |
| B. | omni directional antenna |
| C. | unidirectional antenna |
| D. | low gain antenna |
| Answer» C. unidirectional antenna | |
| 198. |
                   antennas consist of a regular arrangement of antenna elements with a feed network |
| A. | aperture antennas |
| B. | array antennas |
| C. | printed antennas |
| D. | wire antennas |
| Answer» C. printed antennas | |
| 199. |
Power radiated from an antenna per unit solid angle is called radiation intensity. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 200. |
A Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â is a device that converts a guided electromagnetic wave on a transmission line into a plane wave propagating in free space. |
| A. | transmitting antenna |
| B. | receiving antenna |
| C. | radar |
| D. | mixer |
| Answer» B. receiving antenna | |