PhysicsKhaga · Class 6-8
Roshni mod par kaise mude? Paravartan ka khel
Roshni seedhi chalti hai. Phir scientists ne patli si taar ke andar se roshni ko ek chuhe ke dimaag tak kaise pahunchaya?
Socho pehle… phir dekho jawab
Ek khaas kaanch ki patli taar (optical fibre) ke andar roshni deewaron se baar-baar takrakar laut-ti hai, aur zig-zag karke aage badhti rehti hai.
Roshni seedhi line mein chalti hai, isliye chhaaya banti hai. Par jab roshni kisi chamakdaar sateh se takraati hai, toh laut aati hai. Ise paravartan (reflection) kehte hain.
Niyam: roshni jis kone par sateh se takraati hai, usi kone par laut-ti hai. Isse hum andaaza laga sakte hain ki roshni kahan jaayegi.
Optical fibre mein roshni andar ki deewaron se baar-baar laut-ti hai. Isliye taar mude tab bhi roshni andar hi rehti hai. Isi tarah internet ke sandesh bhi fibre mein roshni bankar chalte hain.
2007 mein scientists ne aisi hi fibre se neeli roshni bhej kar ek chuhe ki moonchh hilaayi. Yeh 2026 ke Medicine Nobel wali khoj ka hissa hai.
Ghar pe try karo
Bade ke saath ek chhota sheesha aur torch lo. Torch ki roshni sheeshe par daalo aur deewar par roshni ka dhabba dekho. Sheesha thoda ghumao. Dhabba kidhar gaya? (Roshni kisi ki aankh mein mat daalna.)
Wow!
Tumhare ghar tak aane wala fast internet bhi kaanch ki patli taar mein daudti roshni ho sakta hai!
3 sawaal
- Chamakdaar sateh se roshni ka laut-na kya kehlata hai?
Jawab dekho
Paravartan. Roshni ka sateh se laut-na paravartan (reflection) hai.
- Optical fibre mein roshni aage kaise badhti hai?
Jawab dekho
Andar ki deewaron se baar-baar laut kar. Roshni andar ki deewaron se baar-baar laut-ti hai aur zig-zag aage badhti hai.
- Chhaaya kyun banti hai?
Jawab dekho
Roshni seedhi line mein chalti hai. Roshni seedhi chalti hai, rukawat ke peeche nahi pahunchti, isliye chhaaya banti hai.
NCERT se jodo: NCERT Middle Stage Science — roshni, chhaaya aur paravartan