MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 47 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 Yagi antenna has a driven antenna%! |
| A. | Only |
| B. | With a reflector |
| C. | With one or more directors |
| D. | With a reflector and one or more directors |
| Answer» E. | |
| 2. |
The radiation pattern of Hertzian dipole in the plane perpendicular to dipole is a%! |
| A. | Null |
| B. | Circle |
| C. | Figure of eight |
| D. | None of the above |
| Answer» D. None of the above | |
| 3. |
The attenuation in waveguide above to cut off frequency%! |
| A. | Very high |
| B. | Very low |
| C. | Zero |
| D. | Infinite |
| Answer» C. Zero | |
| 4. |
Parabolic and lens antenna used at%! |
| A. | Microwave frequency |
| B. | Medium frequency |
| C. | Low frequency |
| D. | High frequency |
| Answer» B. Medium frequency | |
| 5. |
When a conductor moves in the field, so that it makes an angle 8 with the lines of flux, the force F is given as : F = Bl sin2 0.%! |
| A. | Yes |
| B. | No |
| Answer» C. | |
| 6. |
Tropospheric scatter is used with frequencies in the%! |
| A. | HF |
| B. | VHF |
| C. | UHF |
| D. | VLF |
| Answer» D. VLF | |
| 7. |
In case of surface waves the field strength at a point is directly proportional to%! |
| A. | Antenna height |
| B. | Wave frequency |
| C. | Current of the antenna |
| D. | Distance of the point from the antenna |
| Answer» E. | |
| 8. |
MUF is highest in periods of greatest sunspot activity.%! |
| A. | True |
| B. | False |
| Answer» B. False | |
| 9. |
The skip distance is the maximum distance upto which ionospheric reflection is possible.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 10. |
Which of the following impedance inversion is obtained?%! |
| A. | Short-circuited stub |
| B. | A quarter wave line |
| C. | Balun transformer |
| D. | A half wave line |
| Answer» C. Balun transformer | |
| 11. |
A rectangular waveguide is a%! |
| A. | Rectangular conducting wire to propagate electromagnetic waves |
| B. | Hollow rectangular walled room carrying electromagnetic wave |
| C. | Hollow rectangular conducting tube through which electromagnetic waves can be propagat-ed |
| D. | Tube antenna to transmit and receive electromagnetic waves |
| Answer» D. Tube antenna to transmit and receive electromagnetic waves | |
| 12. |
In an impedance smith chart, a clockwise movement along a constant resistance circle gives rise to%! |
| A. | Decrease in the value of reactance |
| B. | An increase in the value of reactance |
| C. | No change in the reactance value |
| D. | No change in the impedance value |
| Answer» C. No change in the reactance value | |
| 13. |
The power gain of a half-wave dipole with respect to an isotropic radiator is%! |
| A. | 2.15 db |
| B. | 3 db |
| C. | 4.15 db |
| D. | 6 db |
| Answer» B. 3 db | |
| 14. |
The static electric field in a conductor is%! |
| A. | Zero |
| B. | Unity |
| C. | Infinity |
| D. | None of the above |
| Answer» B. Unity | |
| 15. |
Radiation intensity in a given direction is the%! |
| A. | Energy radiated per square metre |
| B. | Power radiated per square metre |
| C. | Power radiated per unit solid angle in that direction |
| D. | None of the above |
| Answer» D. None of the above | |
| 16. |
Which of the following statement regarding waveguides is incorrect?%! |
| A. | At waveguide can be coupled to a coaxial cable |
| B. | At frequencies below the cut off value the wave progresses across the waveguide after total reflections |
| C. | Waveguides are usually air filled hollow conducting metallic tubes for transmitting UHF and microwaves |
| D. | Waveguides can handle large power at UHF and microwaves |
| Answer» B. At frequencies below the cut off value the wave progresses across the waveguide after total reflections | |
| 17. |
A square corner reflector is used in which of the following?%! |
| A. | TV broadcast |
| B. | Point-to-point communication |
| C. | Radio astronomy |
| D. | All of the above |
| Answer» E. | |
| 18. |
In microwave communication links, when fading due to rain attenuation occurs then technique adopted for solving the problem would include%! |
| A. | Antenna replacement and feed correction |
| B. | Amplitude timing and phase correction |
| C. | Polarization shifting and code diversity |
| D. | Path diversity and frequency diversity |
| Answer» E. | |
| 19. |
The frequency range for satellite communication is%! |
| A. | 3 to 30 kHz |
| B. | 300 to 3000 kHz |
| C. | 3000 to 30000 MHz |
| D. | 30000 to 300000 MHz |
| Answer» D. 30000 to 300000 MHz | |
| 20. |
The wave in wave guide has%! |
| A. | Group velocity inversely proportional to wavelength |
| B. | Larger frequency than in the free space |
| C. | Diminishing wavelength than in the free space |
| D. | Larger wavelength than in the free space |
| Answer» E. | |
| 21. |
The critical frequency of ‘F’ layer is greater than 30 MHz.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 22. |
Tropospheric scatter propagation is not subject to any fading.%! |
| A. | True |
| B. | False |
| Answer» C. | |
| 23. |
A square corner reflector is used in%! |
| A. | Radio astronomy |
| B. | Tv broadcast |
| C. | Point to point communication |
| D. | All of the above |
| Answer» E. | |
| 24. |
In case of antenna the ratio of the power radiated in the desired direction to the power radiated in the opposite direction is known as%! |
| A. | Transmission efficiency |
| B. | Front to back ratio |
| C. | Loss coefficient |
| D. | None of the above |
| Answer» C. Loss coefficient | |
| 25. |
A waveguide operated below cut off frequency can be used as%! |
| A. | Phase shifter |
| B. | An attenuator |
| C. | An isolator |
| D. | None |
| Answer» C. An isolator | |
| 26. |
The minimum height of outer atmosphere is%! |
| A. | 100 km |
| B. | 150 km |
| C. | 200 km |
| D. | 400 km |
| Answer» E. | |
| 27. |
*$_The minimum height of outer atmosphere is? |
| A. | 100 km |
| B. | 150 km |
| C. | 200 km |
| D. | 400 km |
| Answer» E. | |
| 28. |
*/*_An open wire transmission line having a characteristic impedance of 600 ohms is terminated by a resistive load of 900 O. The standing wave ratio will be? |
| A. | 1.5 |
| B. | 2.5 |
| C. | 3.5 |
| D. | 4.5 |
| Answer» B. 2.5 | |
| 29. |
*/*_According to maximum power transfer theorem, the maximum power is absorbed by one network from another network when? |
| A. | The impedance of one of the networks is half that of the other |
| B. | The impedance of one is the complex conjugate of the other |
| C. | The impedance of one is equal to that of the other |
| D. | None of the above |
| Answer» C. The impedance of one is equal to that of the other | |
| 30. |
*/*_The main disadvantage of the two-hole directional coupler is? |
| A. | Poor directivity |
| B. | Narrow bandwidth |
| C. | High standing wave ratio |
| D. | Low directional coupling |
| Answer» C. High standing wave ratio | |
| 31. |
*/*_When a wave is incident from the more dense into a less dense medium at an angle equal to or exceeding the critical angle, the wave suffers total internal __________ .? |
| A. | Reflection |
| B. | Refraction |
| C. | Transmission |
| D. | None of the above |
| Answer» C. Transmission | |
| 32. |
%_The potential that appears at a point in space due to the current which caused it is called potential_% |
| A. | Accelerating |
| B. | Retardation |
| C. | Oscillating |
| D. | Lagging the current |
| Answer» C. Oscillating | |
| 33. |
_ Which of the following is multiband HF receiving antenna?$? |
| A. | Square loop |
| B. | Log-periodic |
| C. | Conical horn |
| D. | Folded dipole |
| Answer» C. Conical horn | |
| 34. |
_ Which of the following will increase the antenna radiation efficiency?$? |
| A. | Use of larger section of conductor |
| B. | Providing insulation on conductor |
| C. | Top loading of antenna |
| D. | Any of the above |
| Answer» D. Any of the above | |
| 35. |
_ A satellite that simply reflect back the signals from one region of the earth to the other region is known as$? |
| A. | Orbiting satellite |
| B. | Geostationary satellite |
| C. | Active satellite |
| D. | Passive satellite |
| Answer» E. | |
| 36. |
_ If a and b are the dimensions of waveguide then$? |
| A. | a = 3b |
| B. | a = 2b |
| C. | a = b |
| D. | a = b/4 |
| Answer» C. a = b | |
| 37. |
__Which antenna is a wideband antenna?__ |
| A. | Hertz antenna |
| B. | Marconi antenna |
| C. | Folded dipole |
| D. | None of the above |
| Answer» D. None of the above | |
| 38. |
_In H-plane metal plate lens the travelling wave front is$? |
| A. | Totally retarded |
| B. | Retarded |
| C. | Accelerated |
| D. | Neither accelerated nor retarded |
| Answer» C. Accelerated | |
| 39. |
_The transmitting antennas for lower frequencies (below 500 kHz) are generally$? |
| A. | Vertical grounded wire type |
| B. | Horizontal suspended wire type |
| C. | Parabolic reflector type |
| D. | Any of the above |
| Answer» B. Horizontal suspended wire type | |
| 40. |
_When the phase velocity of an EM wave depends on frequency in any medium the phenomenon is called$? |
| A. | Scattering |
| B. | Polarisation |
| C. | Absorption |
| D. | Dispersion |
| Answer» C. Absorption | |
| 41. |
_When a current carrying conductor is brought into magnetic field, the force that moves the conductor depends upon$? |
| A. | The value of current |
| B. | The weight of the conductor |
| C. | The direction of the conductor |
| D. | None of the above |
| Answer» B. The weight of the conductor | |
| 42. |
The divergence of a vector is a scalar, while the curl of a vector is another$? |
| A. | Scalar |
| B. | Vector |
| C. | Unit vector |
| D. | None of the above |
| Answer» C. Unit vector | |
| 43. |
The divergence of a vector is a scalar, while the curl of a vector is another? |
| A. | Scalar |
| B. | Vector |
| C. | Unit vector |
| D. | None of the above |
| Answer» C. Unit vector | |
| 44. |
It is best to use for coupling a coaxial line to a parallel wire transmission line.? |
| A. | Directional Coupler |
| B. | Balun |
| C. | Slotted line |
| D. | Tee |
| Answer» C. Slotted line | |
| 45. |
The virtual height of an ionospheric layer is __________ true height? |
| A. | Equal to |
| B. | Less than |
| C. | Higher than |
| D. | No relation |
| Answer» D. No relation | |
| 46. |
The useful magnetic flux obtainable from any closed surface is? |
| A. | Unity |
| B. | Constant |
| C. | Both A and B |
| D. | None of the above |
| Answer» E. | |
| 47. |
The radiation pattern of loop antenna is? |
| A. | Circle |
| B. | Semicircle |
| C. | Elliptical |
| D. | Cardoid or Limacon |
| Answer» E. | |