दूध की शुद्धता का मापन करता है ? - What measures the purity of milk? - Doodh Ki Suddhta Ka Maapan Karta Hai ? General Science in hindi, Physics Manometer question answers in hindi pdf Fedometer questions in hindi, Know About hydrometer General Science online test General Science notes in hindi quiz book Lactometer
Nitrogen is correct answer but argon gas is also used in electric bulbs.. Please mention Nitrogen or argon Thanks
Laxmanlal meena