Explore topic-wise MCQs in Antennas.

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