आन्तरिक ऊर्जा की संकल्पना ऊष्मागतिकी के किस नियम से मिलती है ? - Which law of thermodynamics gives the concept of internal energy? - Antrik Urja Ki Sankalpana ushmagatiki Ke Kis Niyam Se Milti Hai ? General Science in hindi, Physics Pratham Niyam question answers in hindi pdf Dvitiya Niyam questions in hindi, Know About shunyank General Science online test General Science notes in hindi quiz book Third Niyam