TNPSC Free Notes Physics In English – Doppler Effect

இந்தக் கட்டுரையில், TNPSC குரூப் 1, குரூப் 2, குரூப் 2A, குரூப் 4 மாநிலப் போட்டித் தேர்வுகளான TNUSRB, TRB, TET, TNEB போன்றவற்றுக்கான  முறைகள் இலவசக் குறிப்புகளைப் பெறுவீர்கள்.தேர்வுக்கு தயாராவோர் இங்குள்ள பாடக்குறிப்புகளை படித்து பயன்பெற வாழ்த்துகிறோம்.

Doppler Effect

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.

Application of Doppler effect
 To measure the speed of an automobile
 Tracking a satellite
 RADAR (Radio Detection And Ranging)
 SONAR (Sound Navigation and Ranging)
Heat:
 Heat is an energy that raises the temperature of a thing by causing the molecules in that
thing to move faster
 Heat is the total kinetic energy of constituent particles of objects.
 SI Unit of Heat is joule. The unit calorie is also used.

Temperature:
 The measurement of warmness or coldness of a substance is known as its Temperature.
 SI unit of temperature is kelvin. Celsius and Fahrenheit are the other units used.
 Celsius is called as Centigrade as well.

Effects of Heat:
 Expansion
 Increase in temperature
 Change in state
Thermal expansion:
 The expansion of a substance on heating is called, the thermal expansion of that
substance.
 The expansion in length is called linear expansion and the expansion in volume is called
cubical expansion.
 Takes place in all three states (Solids ,liquids and Gases) and maximum in gases.

Applications of thermal expansions:
 Fitting the iron rim on the wooden wheel
 Riveting
 Laying of railway lines.
Change of State:
 Solid to Liquid (Melting)
 Liquid to Gas (Vapourisation)
 Solid to Gas (Sublimation)
 Liquid to Solid (Freezing)
 Gas to Solid (Deposition)

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