Ground waves are not adversely affected by which of the following factors?

Aeronautical & Aerospace Engineering : Avionics - Quiz(MCQ)

Lightning strikes

Day/night changes

Dielectric of earth

Conductivity of earth

Correct Answer : Day/night changes

Explanation : Propagation of ground waves depends on several additional factors. Some of which are conductivity and dielectric constant of earth. Weather changes like thunderstorms and lightning strikes also create extra atmospheric noise and degrade signal.

Recently Updated in Avionics Questions

Which of the following type is not used in an Omega system?

Valley span

Insulated tower

Hanging tower

Grounded tower

Correct Answer : Option (C) : Hanging tower

Explanation : Since the Omega stations transmit in very low frequencies, the antennas are the largest physical structures in the stations. Three types of antennas are employed in the Omega system: grounded tower, insulated tower, and the valley span.

_____ acts as a coarse tuning device for the antenna?

Loop

Helix

Filters

Amplifiers

Correct Answer : Option (B) : Helix

Explanation : The RF signal that is to be transmitted is transferred to the ‘Helix,’ a large helical coil that acts as a coarse tuning device for the antenna. The helix is equipped with separate taps for each signal frequency transmitted.

What type of transmission is used in Omega system?

Phase modulated wave

Continuous wave

Amplitude modulated wave

Frequency modulated wave

Correct Answer : Option (B) : Continuous wave

Explanation : At each Omega station, continuous wave signals on four common frequencies and one station unique frequency. The signal frequencies are time shared among the stations so that a given frequency is transmitted by only one station at any given time.