Prism Aur Dispersion - Class 10 Science

Safed Roshni Safed Nahi Hai! ⚪

Sooraj ki roshni aapko safed dikhti hai. Bulb ki roshni bhi. Par 350 saal pehle Isaac Newton ne sabit kar diya ki safed roshni asal mein safed hai hi nahi — wo saat rangon ka mel hai!

🔬 Newton Ka Andhera Kamra

1666 mein Cambridge University plague (mahamari) ki wajah se band ho gayi. Newton apne gaon Woolsthorpe chale gaye — aur wahan unhone apni zindagi ke sabse bade prayog kiye. (Wahi saal jab seb wali kahani bhi hui thi.)

Unhone kamre ko poori tarah andhera kiya aur khidki mein ek chhota sa chhed banaya. Us patli si safed roshni ko unhone ek kaanch ke prism se guzaara — aur deewar par saat rangon ki patti ban gayi!

Par yahan log ruk jaate the. Us zamaane mein sab maante the ki "kaanch ne roshni ko rang de diya". Newton ne ise galat sabit karne ke liye ek aur prayog kiya — aur wahi asli kamaal tha.

📌 Dispersion (vikiran): safed roshni ka apne saat rangon mein bat jaana.

Bane hue rangon ki patti ko SPECTRUM kehte hain.

Rangon ka kram yaad karne ke liye: VIBGYOR
Violet, Indigo, Blue, Green, Yellow, Orange, Red

🔺 Rang Alag Kyun Hote Hain?

Yaad karo, refraction (apvartan) ka asli kaaran kya tha? Roshni ki raftaar ka badalna. Ab ek nayi baat: kaanch ke andar har rang ki raftaar alag hoti hai!

Prism har rang ko alag-alag kon par modta hai. Red sabse kam, violet sabse zyada — isi se saat rang alag dikhne lagte hain.

📌 Poora kaaran do line mein:

🔹 Kaanch mein RED sabse tez chalta hai → uska refractive index (apvartanank) sabse kam → wo sabse kam mudta hai
🔹 Kaanch mein VIOLET sabse dheema chalta hai → refractive index sabse zyada → wo sabse zyada mudta hai

Baaki paanch rang inke beech mein aate hain. Bas — yahi poora dispersion hai.

⚠️ Zaroori: hawa (ya vacuum) mein saare rang barabar tez chalte hain! Isiliye hawa mein dispersion hota hi nahi. Rang tabhi alag hote hain jab wo kisi ghane medium (maadhyam) mein ghusein.

🎨 Rang aur wavelength ka rishta

Har rang ki apni wavelength (tarang-dairghya) hoti hai:

🔴 Red — sabse lambi wavelength (~700 nm)
🟣 Violet — sabse chhoti wavelength (~400 nm)

Aur yahi ek baat aage do aur cheezein samjhaayegi:
🔹 Chhoti wavelength zyada mudti hai (dispersion — is lesson mein)
🔹 Chhoti wavelength zyada bikharti hai (scattering — aakhri lesson mein, jisse aasman neela dikhta hai)

Ek hi baat, do bade nateeje!

🔬 Newton Ka Doosra Prism — Asli Saboot

Newton ke waqt log kehte the: "kaanch ne roshni ko rang diya hoga." Newton ne ise galat sabit karne ke liye do zabardast prayog kiye:

🧪 Prayog A — Ek rang ko dobara prism mein bhejo

Newton ne spectrum mein se sirf ek rang (jaise hara) chuna aur use ek doosre prism mein bheja.

Agar kaanch sach mein rang "banata" hota, toh us hare rang se aur naye rang nikalne chahiye the.

Par kuch nahi hua! Hara rang hara hi raha, bas thoda muda. Matlab hara rang shuddh (pure) hai — use aur toda nahi ja sakta.

🧪 Prayog B — Do prism ulte-seedhe (Board ka favourite)

Phir Newton ne ek doosra prism ULTA karke pehle wale ke saamne rakh diya.

Pehle prism ne saat rang alag kiye. Doosre prism ne un saaton rangon ko wapas jod diya — aur doosri taraf se phir se SAFED roshni nikli!

✅ Isse do baatein sabit ho gayin:
1️⃣ Kaanch rang banata nahi — wo sirf pehle se maujood rangon ko alag karta hai
2️⃣ Safed roshni asal mein saat rangon ka mel hai

Doosra ulta prism saaton rangon ko wapas jod deta hai — aur safed roshni phir se ban jaati hai.

🌈 Rainbow Kaise Banta Hai

Rainbow prakriti ka apna dispersion ka prayog hai. Aur usme prism ki jagah kaam karti hain baarish ki chhoti-chhoti boondein.

📌 Har boond mein teen cheezein hoti hain — usi kram mein:

1️⃣ REFRACTION + DISPERSION — roshni boond mein ghusti hai, mudti hai aur saat rangon mein bat jaati hai
2️⃣ TOTAL INTERNAL REFLECTION (paraavartan) — rang boond ki peechhe wali deewar se wapas uchhal jaate hain
3️⃣ REFRACTION — bahar nikalte waqt wo phir mudte hain aur aur alag ho jaate hain

Isiliye rainbow banne ke liye refraction, dispersion aur total internal reflection — teeno chahiye!

Ek boond ke andar teen kaam hote hain. Roshni jis taraf se aayi thi, usi taraf lautti hai — isiliye rainbow hamesha sooraj ke ULTI taraf dikhta hai.

🌦️ Rainbow ke baare mein 4 mazedaar baatein

1️⃣ Rainbow hamesha sooraj ke ulti taraf hota hai. Isiliye rainbow dekhne ke liye aapki peeth sooraj ki taraf honi chahiye.

2️⃣ Rainbow asal mein poora gol (circle) hota hai! Hume aadha isliye dikhta hai kyunki zameen neeche wala hissa kaat deti hai. Hawai jahaz se dekho toh poora gola dikh sakta hai.

3️⃣ Har vyakti apna alag rainbow dekhta hai! Rainbow kisi khaas jagah par nahi hota — wo un boondon se banta hai jo aapki aankh ke sahi kon par hain. Aapke bagal khade dost ka rainbow alag boondon se ban raha hai.

4️⃣ Kabhi-kabhi doosra dhundhla rainbow bhi dikhta hai. Wo tab banta hai jab boond ke andar TIR do baar ho jaata hai — aur usme rang ULTE kram mein hote hain (red andar, violet bahar)!

🇮🇳 India Connection

Bharat ke prachin granthon mein rainbow ko "Indradhanush" (Indra ka dhanush) kaha gaya hai — aur ye naam aaj bhi chalta hai.

Par sirf naam nahi — 13vi shatabdi mein Kamal al-Din al-Farisi (jinka kaam bharat aur arab duniya dono mein padha gaya) ne paani se bhare ek bade paardarshi gole ko ek "badi boond" maankar prayog kiye, aur sahi-sahi bata diya ki rainbow do refraction aur ek internal reflection se banta hai — Newton se lagbhag 400 saal pehle!

Aur aaj bharat sarkaar ka bachchon ke tikakaran (vaccination) wala mission bhi "Mission Indradhanush" kehlata hai — kyunki usme saat bimariyon se bachaav hota hai, rainbow ke saat rangon ki tarah.

🧠 Apne Aap Ko Test Karo

Q1. Dispersion ka kya matlab hai?

Q2. Prism mein kaunsa rang SABSE ZYADA mudta hai?

Q3. Rang alag-alag mudte kyun hain?

Q4. Newton ne doosra ULTA prism rakh kar kya dikhaya?

Q5. Rainbow banne ke liye ek boond mein kya-kya hota hai?

Q6. Rainbow dekhne ke liye aapki peeth kis taraf honi chahiye?

🌈 Prism Explorer mein safed light ko todo aur phir wapas jodo!

Open Prism Explorer →

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