Which of the following is not an advantage of NDB?

Aeronautical & Aerospace Engineering : Avionics - Quiz(MCQ)

Inexpensive

Omnidirectional

Accuracy depends on airborne equipment

No mountain and night effect

Correct Answer : No mountain and night effect

Explanation : NDB uses ground waves which follow the curvature of earth. They are inexpensive and independent of accuracy issues but suffer from night effect and mountain effect. Mountain effect is the distortion of ground wave in terrain of nonuniform character.

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.