MCQOPTIONS
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MCQOPTIONS
This section includes 69 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. |
A high-power microwave pulse of the order of megawatts can be generated by a%! |
| A. | Traveling-wave tube |
| B. | Magnetron |
| C. | Reflex klystron |
| D. | Gunn diode |
| Answer» C. Reflex klystron | |
| 2. |
If k-factor is greater than 1, the array beam is bent%! |
| A. | Away from the earth |
| B. | Towards the ionosphere, |
| C. | Towards the earth |
| D. | Towards the outer space |
| Answer» D. Towards the outer space | |
| 3. |
In a pulsed radar set, the function of the duplexer is to%! |
| A. | Aid in calibrating the display unit |
| B. | Prevent frequency drift in the klystron |
| C. | Allow the transmitter and the receiver to operate from a common antenna |
| D. | All of these |
| Answer» D. All of these | |
| 4. |
At what position is the input signal inserted into a traveling-wave tube?%! |
| A. | At the cathode end of the helix |
| B. | At the collector |
| C. | At the collector end of the helix |
| D. | At the control grid of the electron gun |
| Answer» B. At the collector | |
| 5. |
__________ is the progressive decrease of signal strength with increasing distance.%! |
| A. | Radiation |
| B. | Attenuation |
| C. | Modulation |
| D. | Propagation |
| Answer» C. Modulation | |
| 6. |
The coarse frequency adjustment of a reflex klystron is accomplished by%! |
| A. | The AFC system |
| B. | Adjusting the flexible wall of the resonant cavity |
| C. | An adjustment in the synchronizer |
| D. | Varying the repeller voltage |
| Answer» C. An adjustment in the synchronizer | |
| 7. |
Which of the reception problems below that is not due to multipath?%! |
| A. | Delayed spreading |
| B. | Rayleigh fading |
| C. | Random Doppler shift |
| D. | Slow fading |
| Answer» E. | |
| 8. |
The highest frequency which a conventional vacuum tube oscillator can generate is not limited by the%! |
| A. | Electron transit time |
| B. | Distributed lead inductance |
| C. | Inter-electrode capacitance |
| D. | Degree of emission from the cathode |
| Answer» E. | |
| 9. |
*$_The coarse frequency adjustment of a reflex klystron is accomplished by? |
| A. | The AFC system |
| B. | Adjusting the flexible wall of the resonant cavity |
| C. | An adjustment in the synchronizer |
| D. | Varying the repeller voltage |
| Answer» C. An adjustment in the synchronizer | |
| 10. |
*$_Which of the reception problems below that is not due to multipath?? |
| A. | Delayed spreading |
| B. | Rayleigh fading |
| C. | Random Doppler shift |
| D. | Slow fading |
| Answer» E. | |
| 11. |
*$_The highest frequency which a conventional vacuum tube oscillator can generate is not limited by the? |
| A. | Electron transit time |
| B. | Distributed lead inductance |
| C. | Inter-electrode capacitance |
| D. | Degree of emission from the cathode |
| Answer» E. | |
| 12. |
*$_At what position is the input signal inserted into a traveling-wave tube?? |
| A. | At the cathode end of the helix |
| B. | At the collector |
| C. | At the collector end of the helix |
| D. | At the control grid of the electron gun |
| Answer» B. At the collector | |
| 13. |
*$_A high-power microwave pulse of the order of megawatts can be generated by a? |
| A. | Traveling-wave tube |
| B. | Magnetron |
| C. | Reflex klystron |
| D. | Gunn diode |
| Answer» C. Reflex klystron | |
| 14. |
*$_If k-factor is greater than 1, the array beam is bent? |
| A. | Away from the earth |
| B. | Towards the ionosphere, |
| C. | Towards the earth |
| D. | Towards the outer space |
| Answer» D. Towards the outer space | |
| 15. |
*$_In a pulsed radar set, the function of the duplexer is to? |
| A. | Aid in calibrating the display unit |
| B. | Prevent frequency drift in the klystron |
| C. | Allow the transmitter and the receiver to operate from a common antenna |
| D. | All of these |
| Answer» D. All of these | |
| 16. |
*$___________ is the progressive decrease of signal strength with increasing distance.? |
| A. | Radiation |
| B. | Attenuation |
| C. | Modulation |
| D. | Propagation |
| Answer» C. Modulation | |
| 17. |
*/*_What allow microwave to pass in only one direction?? |
| A. | RF emitter |
| B. | Capacitor |
| C. | Varactor-triac |
| D. | Ferrite emitter |
| Answer» E. | |
| 18. |
*/*_It is possible to increase the maximum range of a radar equipment by? |
| A. | Lowering the pulse frequency |
| B. | Raising the peak power of the transmitter |
| C. | Narrowing the beam width and increasing the pulse duration |
| D. | All of these |
| Answer» E. | |
| 19. |
*/*_Which causes multipath or frequency selective fading?? |
| A. | Small reflector |
| B. | Nearer reflector |
| C. | Further reflector |
| D. | Large reflector |
| Answer» E. | |
| 20. |
*/*_As the electron beam moves through a klystron’s intercavity drift space? |
| A. | Frequency modulation at the input cavity creates velocity modulation at the output cavity |
| B. | Velocity modulation at the input cavity creates density modulation at the output cavity |
| C. | Density modulation at the input cavity creates velocity modulation at the output cavity |
| D. | Phase modulation at the input cavity creates velocity modulation at the output cavity. |
| Answer» C. Density modulation at the input cavity creates velocity modulation at the output cavity | |
| 21. |
*/*_What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna?? |
| A. | Isolator |
| B. | Magnetron |
| C. | Simplex |
| D. | Circulator |
| Answer» E. | |
| 22. |
*/*_Which of the following is used as a high power microwave oscillator?? |
| A. | Thyratron |
| B. | Magnetron |
| C. | Klystron |
| D. | Reflex-klystron |
| Answer» C. Klystron | |
| 23. |
*/*_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target.? |
| A. | Which may be used to tune the radar synchronizer |
| B. | Which may be used to tune the radar receiver |
| C. | To the tone of the pulse repetition |
| D. | Tune the magnetron to the correct frequency |
| Answer» C. To the tone of the pulse repetition | |
| 24. |
*/*_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be? |
| A. | A decrease in range |
| B. | A reduction in horizontal resolution |
| C. | No noticeable effect |
| D. | A decrease in gain |
| Answer» D. A decrease in gain | |
| 25. |
*/*_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is? |
| A. | A narrow, antenna-beam width in the vertical plane |
| B. | A narrow, antenna-beam width in the horizontal plane |
| C. | A low repetition rate |
| D. | A high duty cycle |
| Answer» C. A low repetition rate | |
| 26. |
%_When used in conjunction with a radar set, the purpose of an echo box is to provide an artificial target._% |
| A. | Which may be used to tune the radar synchronizer |
| B. | Which may be used to tune the radar receiver |
| C. | To the tone of the pulse repetition |
| D. | Tune the magnetron to the correct frequency |
| Answer» C. To the tone of the pulse repetition | |
| 27. |
%_A thin layer of dirt and grime coverts the reflecting surface of the parabolic dish of a radar set. The particular effect on the performance of the radar will be_% |
| A. | A decrease in range |
| B. | A reduction in horizontal resolution |
| C. | No noticeable effect |
| D. | A decrease in gain |
| Answer» D. A decrease in gain | |
| 28. |
%_To achieve good bearing resolution when using a pulsed-radar set, an important requirement is_% |
| A. | A narrow, antenna-beam width in the vertical plane |
| B. | A narrow, antenna-beam width in the horizontal plane |
| C. | A low repetition rate |
| D. | A high duty cycle |
| Answer» C. A low repetition rate | |
| 29. |
%_What ferrite device can be used instead of duplexer of isolate microwave transmitter and receiver when both are connected to the same antenna?_% |
| A. | Isolator |
| B. | Magnetron |
| C. | Simplex |
| D. | Circulator |
| Answer» E. | |
| 30. |
%_It is possible to increase the maximum range of a radar equipment by_% |
| A. | Lowering the pulse frequency |
| B. | Raising the peak power of the transmitter |
| C. | Narrowing the beam width and increasing the pulse duration |
| D. | All of these |
| Answer» E. | |
| 31. |
%_Which causes multipath or frequency selective fading?_% |
| A. | Small reflector |
| B. | Nearer reflector |
| C. | Further reflector |
| D. | Large reflector |
| Answer» E. | |
| 32. |
%_As the electron beam moves through a klystron’s intercavity drift space_% |
| A. | Frequency modulation at the input cavity creates velocity modulation at the output cavity |
| B. | Velocity modulation at the input cavity creates density modulation at the output cavity |
| C. | Density modulation at the input cavity creates velocity modulation at the output cavity |
| D. | Phase modulation at the input cavity creates velocity modulation at the output cavity. |
| Answer» C. Density modulation at the input cavity creates velocity modulation at the output cavity | |
| 33. |
%_Which of the following is used as a high power microwave oscillator?_% |
| A. | Thyratron |
| B. | Magnetron |
| C. | Klystron |
| D. | Reflex-klystron |
| Answer» C. Klystron | |
| 34. |
_ The aquadag coating on the inside of PPI tube is used$? |
| A. | To focus the beam of primary electrons |
| B. | To shield the electron beam from unidirectional magnetic |
| C. | As a second anode and to prevent the build-up of secondary field |
| D. | All of these |
| Answer» D. All of these | |
| 35. |
_The frequency of the oscillation generated by a magnetron, is mainly determined by$? |
| A. | The flux density of the external magnet |
| B. | The ratio of the dc cathode voltage to the magnetic flux density |
| C. | The number of the cavity resonators |
| D. | The dimension of each cavity resonator |
| Answer» E. | |
| 36. |
_A Class-S Emergency Position-Indicating Radio Beacon (E.P.I.R.B)$? |
| A. | Must be capable of floating or being secured to a survival |
| B. | Must have its battery replaced after emergency use |
| C. | May be tested during the first five minutes of any hour |
| D. | All of these |
| Answer» E. | |
| 37. |
_In an SHF pulsed radar set, a reflex klystron can be used as a$? |
| A. | Single mixer stage |
| B. | Local oscillator |
| C. | Transmitter oscillator |
| D. | Duplexer stage |
| Answer» C. Transmitter oscillator | |
| 38. |
_The cavity resonator$? |
| A. | Is equivalent to an LC resonant circuit |
| B. | In a reflect klystron has its output taken from the reflector plate |
| C. | Produces a frequency which is independent of the cavity size. |
| D. | Has a low Q factor for narrow operation. |
| Answer» B. In a reflect klystron has its output taken from the reflector plate | |
| 39. |
_A PPI cathode-ray tube as used on a radar set$? |
| A. | Is used to check the percentage of modulation |
| B. | Indicates both the range and azimuth of a target |
| C. | Indicates only the range of a target |
| D. | Is used for receiver alignment |
| Answer» C. Indicates only the range of a target | |
| 40. |
_In a pulsed radar set, the STC circuit is used to$? |
| A. | Improve the target bearing resolution |
| B. | Increases receiver sensitivity for echoes from targets |
| C. | Vary the pulse frequency in order to control the maximum target |
| D. | Reduce interference from the effects of sea return |
| Answer» E. | |
| 41. |
_The main frequency determining element of a klystron is$? |
| A. | The repeller voltage |
| B. | The accelerating voltage |
| C. | Its resonant cavity |
| D. | Its mode of operation |
| Answer» D. Its mode of operation | |
| 42. |
_Which of the following is used as an oscillator device in the SHF band?$? |
| A. | Thyratron tube |
| B. | Tunnel diode |
| C. | Klystron tube |
| D. | Both B and C |
| Answer» E. | |
| 43. |
_The antenna separations (in meters) required for optimum operation of a space diversity system can be calculated from:where R = effective earth radius (m) and L = path length (m)$? |
| A. | S = 2λR/L |
| B. | S = 3λR/L |
| C. | S = λR/RL |
| D. | S = λR/L |
| Answer» C. S = ≈í¬™R/RL | |
| 44. |
Oscillators of a klystron tube are maintained$? |
| A. | By bunches of electrons passing the cavity grids |
| B. | By plate-to-cathode feedback |
| C. | By feedback between the accelerating grid and the repeller |
| D. | By circulating bunches of electrons within the cavities. |
| Answer» B. By plate-to-cathode feedback | |
| 45. |
Rainfall is an important factor for fading of radio waves at frequencies above$? |
| A. | 10 GHz |
| B. | 100 GHz |
| C. | 1 GHz |
| D. | 100 MHz |
| Answer» B. 100 GHz | |
| 46. |
Which of the following permits a microwave signal to travel in one direction with virtually no loss, but severely attenuates any signal attempting to travel in the reverse direction?$? |
| A. | Isolator |
| B. | Wave trap |
| C. | Tunnel diode |
| D. | Circulator |
| Answer» B. Wave trap | |
| 47. |
In microwave transmission using digital radio, what causes most intersymbol interference?$? |
| A. | Delayed spreading |
| B. | Rayleigh fading |
| C. | Random Doppler shift |
| D. | Slow fading |
| Answer» B. Rayleigh fading | |
| 48. |
Microwave frequencies are normally regarded as those in the range of$? |
| A. | 1 to 500 MHz |
| B. | 1000 to 10,000 GHz |
| C. | 1 to 100 GHz |
| D. | 10 to 1000 GHz |
| Answer» D. 10 to 1000 GHz | |
| 49. |
If the duration of the radar transmitted pulse, on a particular range of operation, is increased, the required bandwidth of the receiver’s IF amplifiers$? |
| A. | Must remain as before |
| B. | Must be increased |
| C. | May be decreased |
| D. | Must be doubled |
| Answer» D. Must be doubled | |
| 50. |
The maximum usable range of the usual radar set (on any particular range setting) is determined by$? |
| A. | The width of the transmitted pulses |
| B. | The interval between transmitted pulses |
| C. | The bandwidth of the receiver IF stages |
| D. | The duty cycle |
| Answer» C. The bandwidth of the receiver IF stages | |