DEFINITION
- Whenever there is a relative motion between a source and a listener, the frequency of the sound heard by the listener is different from the original frequency of sound emitted by the source.
- This is known as the “Doppler effect”.
Example
- The whistle of a fast-moving train appears to increase in pitch as it approaches a stationary listener and it appears to decrease as the train moves away from the listener.
- This apparent change in frequency was first observed and explained by Christian Doppler (1803-1853), an Austrian Mathematician and Physicist.
- He observed that the frequency of the sound as received by a listener is different from the original frequency produced by the source whenever there is a relative motion between the source and the listener.
- This is known as the Doppler effect This relative motion could be due to various possibilities as follows:
- The listener moves towards or away from a stationary source
- The source moves towards or away from a stationary listener
- Both source and listener move towards or away from one other
- The medium moves when both source and listener are at rest
Also Read
- Nature of universe / பேரண்டத்தில் இயல்புகள்
- General Scientific Law / பொது அறிவியல் விதிகள்
- Electricity and Electronics / மின்னியல் மற்றும் மின்னணுவியல்
- Elements and Compounds / தனிமங்களும் சேர்மங்களும்
- Carbon / கார்பன்
- Nitrogen and their compounds / நைட்ரஜன் மற்றும் அதன் சேர்மங்கள்
- Fertilizer / உரங்கள்
- Pesticides / களைக்கொல்லி
- Insecticides / பூச்சிக்கொல்லி
- Blood and blood circulation / இரத்தம் மற்றும் இரத்த சுழற்சி மண்டலங்கள்
- Endocrine system reproductive system / நாளமில்லா சுரப்பி மண்டலம், இனப்பெருக்க மண்டலம்