Question

An artificial satellite can be tracked very precisely from the earth by using?
1. Zeeman effect
2. Sonar
3. Doppler effect
4. Radar

Answer 1

Correct Answer - Option 3 : Doppler effect

The correct answer is Doppler effect.

• An artificial satellite can be tracked very precisely from the earth by using Dopper effect.

• The Doppler effect, or Doppler shift, describes the changes in frequency of any kind of sound or light wave produced by a moving source with respect to an observer.
  • Waves emitted by an object travelling toward an observer get compressed — prompting a higher frequency — as the source approaches the observer.
• The reason for the Doppler effect is that when the source of the waves is moving towards the observer, each successive wave crest is emitted from a position closer to the observer than the crest of the previous wave.
• The distance between successive wavefronts is then increased, so the waves "spread out".
• The Doppler effect has several real-world applications. For example, besides police radar, the Doppler effect is used by meteorologists to track storms.
• Doctors even used the Doppler effect to diagnose heart problems.