Parchhaai kaise banti hai?

Roshni seedhi line mein chalti hai

Parchhaai ek seedhi si baat ki wajah se banti hai: roshni seedhi line mein chalti hai. Ise teen maachis ke dabbon se jaancho, jinke andar ki trey mein bilkul ek hi jagah chhed ho. Unhe ek kataar mein aise khada karo ki chhed ek line mein aa jaayein, unke aar-paar torch chamkaao, aur cardboard ki screen pe chamakdaar spot banta hai. Ek dabbe ko zara sa side mein ya upar karo aur spot gaayab, kyunki roshni mudkar agla chhed nahi dhoondh sakti. Isi tarah moambatti ki lau seedhi pipe ke us paar dikhti hai par mudi pipe se kabhi nahi. Teacher ki madad se ek boond doodh waale paani mein kam power ka laser bhi seedhi raah dikhaata hai. Laser kabhi kisi ki aankh ki taraf mat karo.

Alag alag cheezon se roshni

Ab andhere kamre mein torch ki roshni ke raaste mein alag alag cheezein rakho. Saaf kaanch lagbhag saari roshni jaane deta hai: wo transparent hai. Tracing paper sirf thodi roshni jaane deta hai, isliye spot dhundhla hota hai: wo translucent hai. Cardboard, lakdi ya mota kapda bilkul roshni nahi jaane dete: wo opaque hain.

Parchhaai kaise banti hai

Jab koi opaque cheez roshni ke raaste mein khadi hoti hai, to us pe padne waali roshni ruk jaati hai. Roshni cheez ke chaaron or mud nahi sakti, isliye uske peechhe ki jagah tak roshni nahi pahunchti, aur wahan ki satah pe andhera hissa ban jaata hai. Yahi andhera hissa parchhaai hai. Isliye har parchhaai ko teen cheezein chahiye: roshni dene waala srot, raaste mein ek opaque cheez, aur parchhaai girne ke liye ek screen. Rozmarra mein deewarein, farsh aur zameen screen ka kaam karte hain. Opaque cheezein gehri parchhaai banati hain, translucent halki, aur kuch transparent cheezein bhi feeki parchhaai bana deti hain.

Parchhaai ko kya badalta hai?

Torch waale set-up mein ek baar mein ek cheez badlo. Screen, cheez ya roshni hatao, to parchhaai gaayab. Cheez ko torch ki taraf le jao to parchhaai badi aur dhundhli hoti hai; screen ki taraf le jao to chhoti aur saaf. Cheez ko jhukaao to parchhaai ka aakaar badal jaata hai, isliye parchhaai se kabhi cheez pehchaani jaati hai, kabhi nahi. Cheez ko alag rang se rang do, parchhaai utni hi kaali rehti hai.

Hamare aas-paas parchhaaiyan

Tumhari apni parchhaai din bhar badalti hai. Subah aur shaam, jab Sun neeche hota hai, wo lambi hoti hai; dopahar mein, jab Sun upar hota hai, sabse chhoti. Zameen ke paas udti chidiya gehri aur saaf parchhaai banati hai, par aasmaan mein oonchi udti chidiya ki parchhaai itni feeki aur dhundhli hoti hai ki dikhti hi nahi. Parchhaai kala bhi ban sakti hai: deepak aur screen ke beech sapaat kathputliyan hilaakar parchhaai kathputli khel, Karnataka ki Togalu Gombeyaata se Kerala ki Tholpavakoothu tak, India ki purani parampara hai.

Ye kyun zaroori hai

Roshni ka seedhi line mein chalna parchhaai, dhoop ghadi aur grahan tak samjhaata hai. Aage dekho ki mirror roshni ki disha kaise badalta hai reflection aur plane mirror mein, aur ek chhota chhed tasveer kaise banata hai pinhole camera kaise banayein? mein. Textbook ke sawaalon ke jawab Chapter 11 ke NCERT solutions mein hain; poore Chapter 11 ke notes dekho.