MCQOPTIONS
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MCQOPTIONS
This section includes 9294 Mcqs, each offering curated multiple-choice questions to sharpen your Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 8151. |
Assertion (A): Microstrip is very commonly used in microwave integrated circuits.Reason (R): Microstrip has an easy access to the top-surface so that active and passive discrete components can be easily mounted. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 8152. |
In a TWT the amplitude of resultant wave travelling down the helix remains constant |
| A. | True |
| B. | False |
| Answer» C. | |
| 8153. |
In the given figure forward current wave has a magnitude of |
| A. | 0.45 A |
| B. | 0.3 A |
| C. | 0.2 A |
| D. | 0.1 A |
| Answer» C. 0.2 A | |
| 8154. |
In an infinite line the input impedance at every point is equal to characteristic impedance. |
| A. | True |
| B. | False |
| Answer» B. False | |
| 8155. |
Consider the following time parameters Domain growth time constant.Transit time.Dielectric relaxation time in positive mobility regime. Which of the above are used in connection width transferred electron device? |
| A. | 1, 2, and 3 |
| B. | 1 and 2 only |
| C. | 1 and 3 only |
| D. | 2 and 3 only |
| Answer» B. 1 and 2 only | |
| 8156. |
A disadvantage of microstrip line as the connections of compared to strip line is that former |
| A. | do not lend themselves to printed circuit |
| B. | are more likely to radiate |
| C. | are bulky |
| D. | are more expensive and complex |
| Answer» C. are bulky | |
| 8157. |
As frequency increases, the transmission efficiency |
| A. | decreases |
| B. | increases |
| C. | is not affected |
| D. | either (a) or (c) |
| Answer» C. is not affected | |
| 8158. |
The directive gain of a transmitting antenna is proportional to |
| A. | its cross-sectional area |
| B. | square of cross-sectional area |
| C. | square root of cross-sectional area |
| D. | cube root of cross-sectional area |
| Answer» B. square of cross-sectional area | |
| 8159. |
In a loss line RL < Z0, then |
| A. | Reflection coefficient is zero |
| B. | Reflection coefficient is |
| C. | Reflection coefficient is negative |
| D. | Reflection coefficient is positive |
| Answer» D. Reflection coefficient is positive | |
| 8160. |
Assertion (A): A backward wave oscillator can be used as a sweep generator.Reason (R): The frequency of oscillation of a backward wave oscillator can be changed by varying the voltage which controls the beam velocity. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 8161. |
The correct sequence of parts in klystron amplifier are |
| A. | anode, catcher cavity, cathode, buncher cavity |
| B. | cathode, buncher cavity, catcher cavity, cavity |
| C. | anode, buncher cavity, catcher cavity, cathode |
| D. | cathode, catcher cavity, anode, buncher cavity |
| Answer» C. anode, buncher cavity, catcher cavity, cathode | |
| 8162. |
The electric field in a TWT due to applied signal |
| A. | is directed along the helix axis |
| B. | is directed radially from helix axis |
| C. | is inclined to the helix axis by about 60 |
| D. | is inclined to the helix axis by about 45 |
| Answer» B. is directed radially from helix axis | |
| 8163. |
In a line with finite attenuation |
| A. | power transmission is least efficient when there are no standing waves on the line |
| B. | power transmission is most efficient when there are no standing waves on line |
| C. | Load power depends on phase constant |
| D. | standing waves will always exist on the line |
| Answer» C. Load power depends on phase constant | |
| 8164. |
A radar has a maximum range of 120 km. The maximum allowable pulse repetition frequency for unambiguous reception is |
| A. | 1250 |
| B. | 330 |
| C. | 2500 |
| D. | 8330 |
| Answer» B. 330 | |
| 8165. |
The cut off wavelength in circular waveguide |
| A. | guide diameter |
| B. | square of guide diameter |
| C. | cube of guide diameter |
| D. | square root of guide diameter |
| Answer» B. square of guide diameter | |
| 8166. |
In Reflex Klystron oscillator the focussing electrode is at a high potential |
| A. | True |
| B. | False |
| Answer» C. | |
| 8167. |
If antenna diameter is increased four times, the maximum range is increased by a factor of |
| A. | <span class="root">2</span> |
| B. | 2 |
| C. | 4 |
| D. | 0.2 |
| Answer» D. 0.2 | |
| 8168. |
Assertion (A): Gunn diode is a transferred electron device.Reason (R): A Gunn oscillator uses the phenomenon of transferred electron effect. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» C. A is correct but R is wrong | |
| 8169. |
A cavity resonator is |
| A. | a hollow metallic enclosure |
| B. | a hollow enclosure having magnetic material as its walls |
| C. | a hollow enclosure having dielectric material as its walls |
| D. | either (b) or (c) |
| Answer» B. a hollow enclosure having magnetic material as its walls | |
| 8170. |
The skin depth at 1000 MHz as compared to that at 500 MHz is |
| A. | 2 |
| B. | 12 |
| C. | 0.707 |
| D. | 0.5 |
| Answer» D. 0.5 | |
| 8171. |
The HV and other voltage supplies for a TV receiver are obtained from IHVT. The full name for this device is |
| A. | Internal high voltage transformer |
| B. | Integrated high voltage transformer |
| C. | Instant high voltage transformer |
| D. | Interleaved high voltage transformer |
| Answer» C. Instant high voltage transformer | |
| 8172. |
An antenna operates effectively when its dimensions are |
| A. | of the order of magnitude of wavelength to be transmitted |
| B. | very small than the magnitude of wavelength to be transmitted |
| C. | very large than the magnitude of wavelength to be transmitted |
| D. | either (a) or (b) |
| Answer» B. very small than the magnitude of wavelength to be transmitted | |
| 8173. |
The main systems used for generation of SSB are |
| A. | filter method |
| B. | phase cancellation method |
| C. | third method |
| D. | all of the above |
| Answer» E. | |
| 8174. |
In a pulsed RADAR typical value of pulse duration and pulse frequency respectively are |
| A. | 1 s and 50 Hz |
| B. | 1 s and 500 Hz |
| C. | 4 s and 50 Hz |
| D. | 4 s and 500 Hz |
| Answer» C. 4 s and 50 Hz | |
| 8175. |
The mobile unit of a mobile telephone is generally in |
| A. | vehicles |
| B. | |
| C. | office |
| D. | vehicle or pocket |
| Answer» B. pocket | |
| 8176. |
Assertion (A): Water waves are longitudinal but EM waves are transverseReason (R): In an EM wave electric field, magnetic field and propagation are mutually perpendicular. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» C. A is correct but R is wrong | |
| 8177. |
In the human eye, an image persists for a time of about |
| A. | 1 second |
| B. | 0.1 second |
| C. | 0.05 second |
| D. | 0.02 second |
| Answer» E. | |
| 8178. |
The different channels in a TDM receiver are separated by |
| A. | integration |
| B. | differentiation |
| C. | AND gate |
| D. | OR gate |
| Answer» D. OR gate | |
| 8179. |
In a hi-fi system the nonlinear distortion should be less than |
| A. | 10% |
| B. | 5% |
| C. | 2% |
| D. | 1% |
| Answer» E. | |
| 8180. |
A pure tone at 1000 Hz has a dB level of 50 dB. If two such tones exist simultaneously the dB level is about |
| A. | 50 dB |
| B. | 53 dB |
| C. | 100 dB |
| D. | 200 dB |
| Answer» C. 100 dB | |
| 8181. |
At FM demodulator output noise power density |
| A. | increases with frequency |
| B. | decreases with frequency |
| C. | remains unaltered |
| D. | none of the above |
| Answer» B. decreases with frequency | |
| 8182. |
According to CCIR standards, the Vestigial Sideband (VSB) |
| A. | video frequencies upto 4 MHz are transmitted |
| B. | video frequencies upto 5 MHz are transmitted |
| C. | video frequencies upto 5.5 MHz are transmitted |
| D. | video frequencies upto 6 MHz are transmitted |
| Answer» C. video frequencies upto 5.5 MHz are transmitted | |
| 8183. |
Line of sight transmission is used in |
| A. | radio frequencies below 1 MHz |
| B. | VHF only |
| C. | audio signals only |
| D. | VHF and UHF |
| Answer» E. | |
| 8184. |
Some multiplexing arrangements for telephone system are Space multiplexingTime division multiplexingFrequency division multiplexing Which of the above allow transmission of many independent signals over a single channel? |
| A. | 1 only |
| B. | 2 and 3 only |
| C. | 1, 2, 3 |
| D. | 1 and 3 only |
| Answer» C. 1, 2, 3 | |
| 8185. |
Industrial noise has the frequency range of |
| A. | 1 to 100 Hz |
| B. | 200 to 5000 Hz |
| C. | above 200 MHz |
| D. | 1 to 600 MHz |
| Answer» E. | |
| 8186. |
In a circular waveguide TE21 mode has lowest cutoff frequency |
| A. | True |
| B. | False |
| Answer» C. | |
| 8187. |
The number of TV channels which can be accommodated in a spectrum of 300 MHz is about |
| A. | 5 |
| B. | 10 |
| C. | 50 |
| D. | 200 |
| Answer» D. 200 | |
| 8188. |
The noise figure of multicavity klystron amplifier is very low |
| A. | True |
| B. | False |
| Answer» C. | |
| 8189. |
In the given figure the E and H lines in a coaxial cable |
| A. | The radial lines are E lines and circular lines are H lines |
| B. | Radial lines are H lines and circular lines are E lines |
| C. | The directions of E and H lines are wrong |
| D. | Radial lines may be E and H lines depending an direction of current |
| Answer» B. Radial lines are H lines and circular lines are E lines | |
| 8190. |
Assertion (A): The velocity of electromagnetic waves on overhead lines and coaxial cables is the same.Reason (R): Free space has an intrinsic impedance of 377 ohms. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» E. | |
| 8191. |
The main feature of a parametric amplifier is |
| A. | low noise |
| B. | very high gain |
| C. | broad bandwidth |
| D. | both (b) and (c) |
| Answer» D. both (b) and (c) | |
| 8192. |
Assertion (A): PIN diode is commonly used for microwave control.Reason (R): A PIN diode uses heavily doped p and n materials. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» C. A is correct but R is wrong | |
| 8193. |
In a vacuum tube, the transit time of electron between cathode and anode is important at |
| A. | low frequencies |
| B. | high frequencies |
| C. | both (a) and (b) |
| D. | frequencies which are neither very low nor very high |
| Answer» C. both (a) and (b) | |
| 8194. |
A coaxial line has L = 500 nH/m and C = 50 pF/m. The characteristic impedance is |
| A. | 500 |
| B. | 250 |
| C. | 100 |
| D. | 50 |
| Answer» D. 50 | |
| 8195. |
Assertion (A): A line of length and short circuited at far end has an input impedance of infinity.Reason (R): A line of length and short circuited at far end behaves as a parallel resonant circuit. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» B. Both A and R are correct but R is not correct explanation of A | |
| 8196. |
Assertion (A): A quarter wave transformer is used to match a resistive load to a transmission line.Reason (R): A quarter wave transformer is a transmission line of quarter wave length. |
| A. | Both A and R are correct and R is correct explanation of A |
| B. | Both A and R are correct but R is not correct explanation of A |
| C. | A is correct but R is wrong |
| D. | A is wrong but R is correct |
| Answer» C. A is correct but R is wrong | |
| 8197. |
Which of the following terminations makes the input impedance of a line equal to characteristic impedance Z0? |
| A. | line open circuited at far end |
| B. | line terminated in Z |
| C. | <sub>0</sub> |
| D. | line short circuited at far end |
| E. | line terminated in inductance |
| Answer» C. <sub>0</sub> | |
| 8198. |
High speed logic circuits use |
| A. | pulses with very small width |
| B. | pulses with very large width |
| C. | pulses whose width is neither small nor large |
| D. | either (b) or (c) |
| Answer» B. pulses with very large width | |
| 8199. |
In microwave system the function of mode filter is |
| A. | to suppress modes with lower cut off frequencies |
| B. | to suppress modes with higher cut off frequencies |
| C. | to change mode of wave transmission |
| D. | both (b) and (c) |
| Answer» E. | |
| 8200. |
For the strip line in the given figure the capacitance per unit length = |
| A. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/19-216-1.png"> |
| B. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/19-216-2.png"> |
| C. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/19-216-3.png"> |
| D. | <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/19-216-4.png"> |
| Answer» B. <img src="/_files/images/electronics-and-communication-engineering/microwave-communication/19-216-2.png"> | |