Stefan Boltzmann law and Emissivity | video in HINDI

In this Physics video lecture in Hindi on Radiation for class 11 we explained Stefan Boltzmann law of blackbody radiation. During the derivation of the equation for the rate of radiation for any surface we found that it is equal to the product of emissivity of the surface, the Stefan's constant, the surface area and the fourth power of the absolute temperature of the object. Further we defined emissivity of a material. It is the ratio of the rate of radiation emitted through a unit area of the material to the rate of radiation emitted through a unit area of a blackbody under same condition. फिजिक्स के इस वीडियो में हमने Stefan Boltzmann के सिद्धांत पर बात किया है | यह सिद्धांत हमें यह बताता है कि किसी भी एक वस्तु का रेडिएशन का दर कितना होगा |आगे हम एक और मुद्दा जोकि है एमीसीविटी, उस पर भी बात किया है | ************************************** Click to visit the homepage of our channel :    / @edupoint.physics   EduPoint, Dam Road, Chandil, Dist- Seraikela-Kharsawan, Jharkhand, India.