MCQOPTIONS
Saved Bookmarks
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.
| 1. |
An antenna has a field pattern E (θ) =cos θ. cos 2θ. The first null beam width of the antenna is: |
| A. | 450 |
| B. | 900 |
| C. | 1800 |
| D. | 1200 |
| Answer» C. 1800 | |
| 2. |
amplifiers are linear circuits, where the transistor is biased to conduct over the entire range of the input signal cycle. |
| A. | class a amplifiers |
| B. | class b amplifiers |
| C. | class c amplifiers |
| D. | none of the mentioned |
| Answer» B. class b amplifiers | |
| 3. |
is defined as the ratio of input signal to noise ratio to the output signal to noise ratio. |
| A. | noise figure |
| B. | noise temperature |
| C. | snro |
| D. | none of the mentioned |
| Answer» B. noise temperature | |
| 4. |
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 | |
| 5. |
are used in the final stages of radar and radio transmitters to increase the radiated power level. |
| A. | power amplifiers |
| B. | oscillators |
| C. | transistors |
| D. | attenuators |
| Answer» B. oscillators | |
| 6. |
is a microwave device in which the frequency of operation is determined by the biasing field strength. |
| A. | vtm |
| B. | gyratron |
| C. | helix bwo |
| D. | none of the mentioned |
| Answer» C. helix bwo | |
| 7. |
The solid area through which all the power radiated by the antenna is: |
| A. | beam area |
| B. | effective area |
| C. | aperture area |
| D. | beam efficiency |
| Answer» B. effective area | |
| 8. |
If the length of the intrinsic region in IMPATT diode is 2 µm and the carrier drift velocity are 107 cm/s, then the drift time of the carrier is: |
| A. | 10-11 seconds |
| B. | 2×10-11 seconds |
| C. | 2.5×10-11 seconds |
| D. | none of the mentioned |
| Answer» C. 2.5×10-11 seconds | |
| 9. |
To prevent an IMPATT diode from burning, a constant bias source is used to maintain at safe limit. |
| A. | average current |
| B. | average voltage |
| C. | average bias voltage |
| D. | average resistance |
| Answer» B. average voltage | |
| 10. |
In a oscillator, the RF wave travels along the helix from the collector towards the electron gun. |
| A. | interaction oscillator |
| B. | backward wave oscillator |
| C. | magnetrons |
| D. | none o the mentioned |
| Answer» C. magnetrons | |
| 11. |
is a device that converts electrons to photons or vice-versa. |
| A. | antenna |
| B. | electron gun |
| C. | photon amplifier |
| D. | microwave tube |
| Answer» B. electron gun | |
| 12. |
When the separation between two lines that carry the TEM wave approaches λ the wave tends to be radiated. |
| A. | true |
| B. | false |
| Answer» B. false | |
| 13. |
For Colpitts oscillator, the capacitors C1 and C2 in the feedback network are 1 µF and 25 µF respectively. Then the β value of the transistor is: |
| A. | 35 |
| B. | 000.76 |
| C. | 25 |
| D. | 0.0025 |
| Answer» D. 0.0025 | |
| 14. |
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 | |
| 15. |
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» B. limited space charge accumulation mode | |
| 16. |
A class B amplifier consists of transistors in order to conduct the input signal over the entire cycle. |
| A. | 1 |
| B. | 2 |
| C. | 4 |
| D. | 6 |
| Answer» C. 4 | |
| 17. |
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 | |
| 18. |
uses balanced input and output, meaning that there are 2 signal lines, with opposite polarity at each port. |
| A. | differential amplifier |
| B. | distributed amplifier |
| C. | balanced amplifier |
| D. | none of the mentioned |
| Answer» B. distributed amplifier | |
| 19. |
A 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 | |
| 20. |
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 | |
| 21. |
An inductor is operating at frequency of 50 MHz. Its inductance is 0.1 µH, and then the series resistance associated with the inductor is: (Qo=100) |
| A. | 0.31 Ω |
| B. | 1.32 Ω |
| C. | 1 Ω |
| D. | 1.561 Ω |
| Answer» B. 1.32 Ω | |
| 22. |
If the length of the intrinsic region in IMPATT diode is 2 µm and the carrier drift velocity are 107 cm/s, then the nominal frequency of the diode is: |
| A. | 12 ghz |
| B. | 25 ghz |
| C. | 30 ghz |
| D. | 24 ghz |
| Answer» C. 30 ghz | |
| 23. |
The terminal impedance of a dipole antenna is 710 Ω. The terminal impedance of the slot antenna given the intrinsic impedance of air is 377 Ω is: |
| A. | 100 Ω |
| B. | 50 Ω |
| C. | 25 Ω |
| D. | none of the mentioned |
| Answer» C. 25 Ω | |
| 24. |
is defined as the ratio of desired signal power to undesired noise power. |
| A. | signal to noise ratio |
| B. | noise to signal ratio |
| C. | noise figure |
| D. | noise temperature |
| Answer» B. noise to signal ratio | |
| 25. |
In a diode frequency multiplier, an input signal of frequency fo applied to the diode is terminated with at all frequencies other than required harmonic. |
| A. | real impedances |
| B. | reactive impedance |
| C. | complex impedance |
| D. | none of the mentioned |
| Answer» C. complex impedance | |
| 26. |
has a constant power spectral density. |
| A. | white noise |
| B. | gaussian noise |
| C. | thermal noise |
| D. | shot noise |
| Answer» B. gaussian noise | |
| 27. |
When either a voltage or current is applied to the terminals of bulk solid state compound GaAs, a differential is developed in that bulk device. |
| A. | negative resistance |
| B. | positive resistance |
| C. | negative voltage |
| D. | none of the mentioned |
| Answer» B. positive resistance | |
| 28. |
An antenna has a field pattern of E (θ) = cos2 θ, θ varies between 0 and 900. Half power beam width of the antenna is: |
| A. | 330 |
| B. | 660 |
| C. | 12000 |
| D. | none of the mentioned |
| Answer» C. 12000 | |
| 29. |
Gain of power amplifiers with increase in operating frequency. |
| A. | increases |
| B. | decreases |
| C. | increases exponentially |
| D. | decreases exponentially |
| Answer» C. increases exponentially | |
| 30. |
Colpitts oscillator operating at 50 MHz has an inductor in the feedback section of value 0.10µH. then the values of the capacitors in the feedback section is: |
| A. | 100 pf, 100 pf |
| B. | 100 pf, 50 pf |
| C. | 70 pf, 130 pf |
| D. | 80 pf, 60 pf |
| Answer» B. 100 pf, 50 pf | |
| 31. |
is a non linear circuit that converts DC power to an AC waveform of desired frequency based on the oscillator design. |
| A. | attenuator |
| B. | amplifier |
| C. | oscillator |
| D. | none of the mentioned |
| Answer» D. none of the mentioned | |
| 32. |
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 | |
| 33. |
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 | |
| 34. |
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» B. crossed field | |
| 35. |
Directions: The item consists of two statements, one labelled as the ‘Assertion (A)’ and the other as ‘Reason (R)’.You are to examine these two statements carefully and select the answers to the item using the codes given below:Assertion (A): In microwave point-to-point communication systems, parabolic reflector antennas are generally used.Reason (R): A parabolic reflector antenna receiver has the property of focusing all axial rays to its focus andwhen used as transmitter with a feed at the focus, it will generate parallel beams along the axis with a pencil beam radiation pattern. |
| A. | Both A and R individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are individually true but R is not the correct explanation of A | |
| 36. |
Microwave frequencies are used for communication with deep space probes primarily because they do not suffer: |
| A. | Refraction by ionosphere |
| B. | Attenuation in space |
| C. | Velocity distortion and phase distortion |
| D. | Fading |
| Answer» B. Attenuation in space | |
| 37. |
Microwave wave signals propagating along the curvature of earth is Known as : |
| A. | Faraday effect |
| B. | Ionosphere reflection |
| C. | Ducting |
| D. | Tropospheric scatter |
| Answer» D. Tropospheric scatter | |
| 38. |
Directions: The item consists of two statements, one labeled as the ‘Assertion (A)’ and the other as ‘Reason (R)’.You are to examine these two statements carefully and select the answers to the item using the codes given below:Assertion (A): Generally, magnetrons are operated in π modes.Reason (R): Frequency for π mode can be easily separated from adjacent modes. |
| A. | Both A and R individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are individually true but R is not the correct explanation of A | |
| 39. |
Consider the following statements regarding Bunching process in Klystron:1. Bunching occurs in two cavity Klystron amplifiers2. Bunching occurs in multi cavity Klystron amplifiers3. Bunching occurs in reflex Klystron oscillatorsWhich of these statements are correct? |
| A. | 1 and 2 only |
| B. | 2 and 3 only |
| C. | 1 and 3 only |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 40. |
Directions: The item consists of two statements, one labelled as the ‘Assertion (A)’ and the other as ‘Reason (R)’.You are to examine these two statements carefully and select the answers to the item using the codes given below:Assertion (A): In microwave communication links, intensive fading at 18 GHz band occurs due to rain-drop attenuation.Reason (R): Collective scattering from water droplets in the atmosphere will result in diminution of energy in the forward path and this is maximumat the 18 GHz band because the criterion for scattering are more satisfied by the wavelength dimensions at these frequencies. |
| A. | Both A and R individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are individually true but R is not the correct explanation of A | |
| 41. |
Match List I with List IIList IList II(a) Klystron(i) Slow structure(b) Transfer Electron devices(ii) Bunching(c) MESFET(iii) Warm electrons(d) Travelling wave tube(iv) Pinch - off Choose the correct answer from the options given below: |
| A. | (a) - (ii), (b) - (iii), (c) - (iv), (d) - (i) |
| B. | (a) - (i), (b) - (iii), (c) - (ii), (d) - (iv) |
| C. | (a) - (iii), (b) - (ii), (c) - (i), (d) - (iv) |
| D. | (a) - (iv), (b) - (iii), (c) - (ii), (d) - (i) |
| Answer» B. (a) - (i), (b) - (iii), (c) - (ii), (d) - (iv) | |
| 42. |
IMPATT diode is disadvantageous because of: |
| A. | High noise |
| B. | Too many layers |
| C. | Low efficiency |
| D. | Difficulty in growing intrinsic layer |
| Answer» B. Too many layers | |
| 43. |
For the above directional coupler a coupling factor in dB is: |
| A. | \(10\,{\log _{10}}\frac{{{P_1}}}{{{P_4}}}\) |
| B. | \(10\,{\log _{10}}\frac{{{P_1}}}{{{P_2}}}\) |
| C. | \(10\,{\log _{10}}\frac{{{P_2}}}{{{P_4}}}\) |
| D. | \(10\,{\log _{10}}\frac{{{P_1}}}{{{P_3}}}\) |
| Answer» B. \(10\,{\log _{10}}\frac{{{P_1}}}{{{P_2}}}\) | |
| 44. |
Microwave MB-Communication uses_________ amplifier to obtain large gain over wide bandwidth |
| A. | Reflex Klystron |
| B. | Pi-Mode Magnetron |
| C. | Travelling wave Tube |
| D. | All of these |
| Answer» D. All of these | |
| 45. |
For the experimental study of small microwave antennas, a free space environment with minimum interference by external objects, the facilities required are: |
| A. | RF screens, VSWR meter, waveguide twist |
| B. | UHF screens, slotted waveguides, power meter |
| C. | Anechoic chamber, Network analyzer, Pattern recorder |
| D. | Dark room facility, Digital recorder, Bolometer |
| Answer» C. Anechoic chamber, Network analyzer, Pattern recorder | |
| 46. |
Consider the following time parameters in development of solid state devices:1. Domain growth time constant2. Transit time3. Dielectric relaxation timeIn the case of Transferred Electron Devices (TED), which of these are used? |
| A. | 1 and 2 only |
| B. | 2 and 3 only |
| C. | 1 and 3 only |
| D. | 1, 2 and 3 |
| Answer» E. | |
| 47. |
In a Traveling-wave Tube, the velocity of electron beam with respect to the axial velocity of RF field is kept… |
| A. | Lower |
| B. | Higher |
| C. | Equal |
| D. | Any of these |
| Answer» D. Any of these | |
| 48. |
Direction: Given question consists of two statements, one labeled as the 'Assertion (A)' and the other as 'Reason (R)'. You are to examine these two statements carefully and select the answers to these items using the codes given below.Assertion (A): Microwave link repeaters are typically about 50 km apart.Reason (R): The curvature effect of Earth makes a limitation for the distance between two microwave repeaters. |
| A. | Both A and R are individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is NOT the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are individually true but R is NOT the correct explanation of A | |
| 49. |
Find the maximum input voltage of a two cavity klystron amplifier with the following parameters:V0 = 1 KV, I0 = 25 mA, R0 = 40 kΩ, f = 3 GHzGap spacing in either cavity: 1 mmSpacing between two cavities: 4 cmEffective shunt impedance excluding beam loading = 30 kΩJ1(X) = 0.582, X = 1.481 |
| A. | 1.85 V |
| B. | 96.5 V |
| C. | 105 V |
| D. | 75 V |
| Answer» C. 105 V | |
| 50. |
Directions: The item consists of two statements, one labelled as the ‘Assertion (A)’ and the other as ‘Reason (R)’.You are to examine these two statements carefully and select the answers to the item using the codes given below:Assertion (A): The slow wave structure of a TWT is provided with an attenuator.Reason (R): This is done for preventing oscillations in the device. |
| A. | Both A and R individually true and R is the correct explanation of A |
| B. | Both A and R are individually true but R is not the correct explanation of A |
| C. | A is true but R is false |
| D. | A is false but R is true |
| Answer» B. Both A and R are individually true but R is not the correct explanation of A | |