Question

When a low-flying aircraft passes overhead, we sometimes notice a slight shaking of the picture on our TV screen. This is due to
A. Diffraction of the signal received from the antenna
B. Interference of the direct signal received by the antenna with the weak signal reflected by the passing aircraft
C. Change of Magnetic flux occurring due to the passage of aircraft
D. Vibration created by the passage of aircraft

Answer 1

Hint: This problem is based on interference and diffraction and we know that when two different waves(signals) coincide with each other, it produces a kind of wave phenomena like reflection, refraction, interference, or diffraction hence, use this scientific approach to check which option seems to be more appropriate for the given situation. Then, present the answer with a proper explanation.

Complete answer:
As we all know Aircraft need some sort of radar signal for their navigation system to reach an accurate destination. Therefore, when a low-flying aircraft passes overhead, the rays used for navigation purpose by aircraft is interfered with by the signals received by the TV antenna from satellites and sometimes a low-flying aircraft also reflects the direct TV signals. That’s the reason why we experience a slight disturbance on our TV screen which causes blurry images, interrupting voices, and poor image graphics in an animation.

Thus, we can say that the slight shaking on a TV screen is the result of contact of direct signals received by Tv antennas and reflected signals by low-flying aircraft which is called interference.

Hence, the correct option is (B) Interference of the direct signal received by the antenna with the weak signal reflected by the passing aircraft.

Note: We occasionally detect a minor trembling of the TV image when a low-flying aircraft passes over. To select the most appropriate reason behind this cause, it is essential to analyze the given reasons carefully to get an accurate answer. Also, be sure to give precise justifications rather than just generalizations, while writing an explanation of this kind of conceptual problem.