Can the Doppler Effect Cause Changes in Radio Wave Frequency?

In summary, the Doppler effect causes a change in wavelength (and thus frequency) in all types of waves, which is why you can still hear a radio station at its original frequency despite your speed changing. Although the loss in energy is very small, it does occur.
  • #1
shihab-kol
119
8
I have learned that the Doppler effect causes a change in wavelength (and thus frequency) in all types of waves
Suppose there is a radio station transmitting waves of frequency 90 kHz and the antennae in my car is tuned to that frequency.
Then I start to accelerate and thus I am changing my position relative to the station .
Then due to Doppler effect the waves would have to travel a longer distance and thus there has to be a change in frequency of the waves due to energy loss.
But I can still hear the radio at that frequency , why does this happen?
 
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  • #2
[edit] Hello shihab, :welcome: !

This happens because your radio may be tuned to 90 kHz exactly , but it also perfectly receives the 90000.009 HZ the antenna picks up when you are driving towards the sender at 108 km/h, or the 89999.991 Hz when you drive away from it.

In short: because your speed / wave propagation speed is so small (like 30/300000000 in this example)
 
  • #3
So you mean to say that
BvU said:
[edit] Hello shihab, :welcome: !

This happens because your radio may be tuned to 90 kHz exactly , but it also perfectly receives the 90000.009 HZ the antenna picks up when you are driving towards the sender at 108 km/h, or the 89999.991 Hz when you drive away from it.

In short: because your speed / wave propagation speed is so small (like 30/300000000 in this example)
So, you mean to say that as my speed or velocity is very small compared to that of the radio waves that is why the frequency does not change by a huge amount ?
Is the loss in energy small?
Thanks
 
  • #4
shihab-kol said:
So, you mean to say that as my speed or velocity is very small compared to that of the radio waves that is why the frequency does not change by a huge amount ?
Correct. 0.009 Hz really is a very small amount :smile: of shift for a radio wave.
shihab-kol said:
Is the loss in energy small?
What loss in energy ?
 
  • #5
BvU said:
Correct. 0.009 Hz really is a very small amount :smile: of shift for a radio wave.
What loss in energy ?
Okay, I now understand .
Thank You.:smile:
 

Related to Can the Doppler Effect Cause Changes in Radio Wave Frequency?

1. What is the Doppler Effect in radio waves?

The Doppler Effect in radio waves is the phenomenon in which the frequency of a radio wave appears to change when the source of the wave and the observer are in relative motion.

2. How does the Doppler Effect in radio waves occur?

The Doppler Effect in radio waves occurs when there is a change in the distance between the source and the observer. This change in distance causes a change in the wavelength and frequency of the radio waves.

3. What is the significance of the Doppler Effect in radio waves?

The Doppler Effect in radio waves is significant because it allows us to measure the relative speed and direction of a moving object using the changes in the frequency of the radio waves it emits.

4. How does the Doppler Effect in radio waves affect communication?

The Doppler Effect in radio waves can affect communication by causing a shift in the frequency of the radio waves, which can result in distortion or loss of the signal. This is why communication systems often use techniques like frequency hopping to minimize the impact of the Doppler Effect on communication.

5. Can the Doppler Effect in radio waves be observed in everyday life?

Yes, the Doppler Effect in radio waves can be observed in everyday life. For example, the sound of a siren on a moving vehicle appears to change as it passes by, which is caused by the Doppler Effect. Similarly, the frequency of a radio station may be affected when a car is moving towards or away from the broadcast tower.

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