

MCQOPTIONS
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This section includes 10 Mcqs, each offering curated multiple-choice questions to sharpen your Antennas knowledge and support exam preparation. Choose a topic below to get started.
1. |
Duct propagation occurs at __________ |
A. | lower atmospheric layers |
B. | higher atmospheric layers |
C. | ionospheric layers |
D. | any part of the atmospheric layer |
Answer» B. higher atmospheric layers | |
2. |
For duct propagation the necessary condition is ( frac{d }{dh} ) is always +ve. |
A. | False |
B. | True |
Answer» B. True | |
3. |
The wavelength of the EM signal propagation in the T.I.L for duct propagation is _________ |
A. | ( =2.5h_d sqrt{ 10^{-6}} ) |
B. | ( =2.5h_d sqrt{ 10^6} ) |
C. | ( =5.2h_d sqrt{ 10^{-6}} ) |
D. | ( =25h_d sqrt{ 10^{-6}} ) |
Answer» B. ( =2.5h_d sqrt{ 10^6} ) | |
4. |
Condition for duct propagation is _________ |
A. | ( frac{d }{dh} ) is -ve |
B. | ( frac{d }{dh} ) is +ve |
C. | ( frac{d }{dh} ) is zero |
D. | ( frac{d }{dh} ) is unity |
Answer» B. ( frac{d }{dh} ) is +ve | |
5. |
Which of the following represents the plot of height v/s refractive index of elevated surface duct? |
A. | <img alt="The plot of height v/s refractive index of elevated surface duct - option a" class="alignnone size-full wp-image-276354" height="140" src="https://www.sanfoundry.com/wp-content/uploads/2020/05/antennas-questions-answers-space-wave-propagation-duct-propagation-q6a.png" width="135"/> |
B. | <img alt="The plot of height v/s refractive index of elevated surface duct - option b" class="alignnone size-full wp-image-276355" height="109" src="https://www.sanfoundry.com/wp-content/uploads/2020/05/antennas-questions-answers-space-wave-propagation-duct-propagation-q6b.png" width="153"/> |
C. | <img alt="The plot of height v/s refractive index of elevated surface duct - option c" class="alignnone size-full wp-image-276356" height="140" src="https://www.sanfoundry.com/wp-content/uploads/2020/05/antennas-questions-answers-space-wave-propagation-duct-propagation-q6c.png" width="138"/> |
D. | <img alt="The plot of height v/s refractive index of elevated surface duct - option d" class="alignnone size-full wp-image-276357" height="131" src="https://www.sanfoundry.com/wp-content/uploads/2020/05/antennas-questions-answers-space-wave-propagation-duct-propagation-q6d.png" width="142"/> |
Answer» E. | |
6. |
Refractive index of temperature inversion layer is ____________ |
A. | = (n-1+h/r) 10<sup>6</sup> |
B. | = (n+1+h/r) 10<sup>6</sup> |
C. | = (n-1-h/r) 10<sup>6</sup> |
D. | = (n-1-h/r) 10<sup>6</sup> |
Answer» B. = (n+1+h/r) 10<sup>6</sup> | |
7. |
How long the waves due to duct propagation travel following the earth curvature? |
A. | 1000km |
B. | 50m |
C. | 15m |
D. | 5000km |
Answer» B. 50m | |
8. |
In which of the following propagation temperature inversion layer is present? |
A. | Duct wave propagation |
B. | Sky wave propagation |
C. | Tropospheric scattering wave propagation |
D. | Space wave propagation |
Answer» B. Sky wave propagation | |
9. |
Temperature inversion layer occurs due to _____ |
A. | Super refraction |
B. | Reflection |
C. | Diffraction |
D. | Increase in altitude |
Answer» B. Reflection | |
10. |
Duct propagation is due to which layer? |
A. | Temperature Inversion layer |
B. | Higher atmospheric layer |
C. | Ionospheric layer |
D. | Surface water |
Answer» B. Higher atmospheric layer | |