Most Important Notes for Board Exam 2026: Reflection/Refraction, Nature of Roots, Life Processes, Redox Reactions & Heredity

Reflection/Refraction, Nature of Roots, Life Processes, Redox Reactions, Heredity ये सभी विषय कक्षा 10 विज्ञान के सबसे महत्वपूर्ण टॉपिक्स हैं। Reflection/Refraction, Nature of Roots, Life Processes, Redox Reactions, Heredity से जुड़े प्रश्न हर साल बोर्ड परीक्षा में पूछे जाते हैं।

यदि आप Reflection/Refraction, Nature of Roots, Life Processes, Redox Reactions, Heredity को अच्छे से समझ लेते हैं तो आपका साइंस का बेस मजबूत हो जाएगा।

इस लेख में हम Reflection/Refraction, Nature of Roots, Life Processes, Redox Reactions, Heredity से जुड़े महत्वपूर्ण कॉन्सेप्ट, परिभाषाएं और परीक्षा उपयोगी बिंदुओं को सरल भाषा में समझेंगे, जिससे आपकी तैयारी और भी बेहतर हो सके।

Reflection and Refraction of Light (Physics – Full Explanation)

Reflection of Light (प्रकाश का परावर्तन)

Jab light kisi surface (jaise mirror) se takrati hai aur wapas usi medium me laut jaati hai, use reflection kehte hain.

• Incident Ray – jo ray surface par girti hai
• Reflected Ray – jo ray wapas laut ti hai
• Normal – 90° par khinchi imaginary line
• Angle of Incidence (i) – incident ray aur normal ke beech ka angle
• Angle of Reflection (r) – reflected ray aur normal ke beech ka angle

Laws of Reflection

• i = r
• Incident ray, reflected ray aur normal ek hi plane me hote hain

Ye dono laws har reflective surface par apply hote hain.

Class 10 important questions

Types of Reflection

1. Regular Reflection
   Smooth surface (plane mirror) par hota hai. Clear image milti hai.
2. Diffused Reflection
   Rough surface par hota hai. Image clear nahi hoti.

Image Formation by Mirrors

• Plane Mirror:
• Image virtual hoti hai
• Same size
• Lateral inversion (left-right change)
• Concave Mirror:
• Converging mirror
• Real ya virtual dono image bana sakta hai
• Convex Mirror:
• Diverging mirror
• Hamesha virtual, chhoti image

Class 10 questions

Refraction of Light (अपवर्तन)

Jab light ek medium (air) se dusre medium (water, glass) me jaati hai to speed change hoti hai aur direction bend ho jati hai — ise refraction kehte hain.

Kyun hota hai Refraction?

Har medium ka refractive index alag hota hai.Speed kam ya zyada hone ki wajah se ray mudti hai.

Snell’s Law

Important Concepts:

• Agar light rare → denser medium me jaye → normal ki taraf mudti hai
• Denser → rare me jaye → normal se door mudti hai

Nature of Roots (Mathematics – Full Explanation)

Cases

• ✅ Case 1: D > 0
• Do alag real roots milenge
• ✅ Case 2: D = 0
• Do equal real roots milenge
• ❌ Case 3: D < 0
• Koi real root nahi milega

Quadratic Formula

Life Processes (Biology – Full Explanation)

Life processes wo basic activities hain jo jeevan ko maintain karti hain.

1. Nutrition (पोषण)

Food lena aur energy banana nutrition hai

Autotrophic

Plants khud photosynthesis se food banate hain.

Photosynthesis Process:

• Sunlight
• Chlorophyll
• CO₂
• Water

2. Respiration (श्वसन)

Energy release karne ki process.

Aerobic Respiration

Oxygen ke sathZyada ATP energy

• Oxygen ke sath
• Zyada ATP energy

Math

Anaerobic Respiration

• Oxygen ke bina
• Kam energy

3. Transportation

Human body me:

• Heart blood pump karta hai
• Arteries oxygenated blood le jati hain
• Veins deoxygenated blood

Plants me:

• Xylem → water transport
• Phloem → food transport

4. Excretion

Waste materials nikalna.

• Kidney blood filter karti hai
• Urine banta hai

Redox Reactions (Chemistry – Full Explanation)

Redox = Reduction + Oxidation

Oxidation

• Oxygen ka judna
• Hydrogen ka hatna

Class 10

Reduction

• Oxygen ka hatna
• Hydrogen ka judna

Oxidising Agent

Jo dusre ko oxidize kare

Reducing Agent

Jo dusre ko reduce kare

CBSE

Heredity (Biology – Full Explanation)

Heredity traits ka transfer hai parents se children tak.

Basic Terms

• Gene – trait ka unit
• Chromosome – genes ka group
• DNA – genetic material

Mendel’s Experiments

Unhone pea plants par experiment kiya.

Law of Dominance

Ek trait dominant hota hai

Law of Segregation

Traits alag hokar next generation me jate hain

• Tall (TT) × Dwarf (tt)
• Gametes: T, T
• t, t
• Result: All Tt (Tall)

✅ 1. Reflection ke do niyam likhiye.
Answer:
Angle of incidence (i) = Angle of reflection (r).
Incident ray, reflected ray aur normal ek hi plane me hote hain.
✅ 2. Refraction kya hota hai?
Answer:
Jab light ek medium se dusre medium me jaati hai aur uski direction change ho jaati hai to ise refraction kehte hain. Yeh medium ki speed change hone ki wajah se hota hai.

✅ 3. Refractive Index ka formula kya hai?

Refractive index batata hai ki medium me light kitni slow ho jaati hai.

✅ 4. Discriminant kya hota hai?
Answer:
Quadratic equation me � ko discriminant kehte hain. Ye roots ki nature batata hai.
✅ 5. Agar D < 0 ho to roots ki nature kya hogi?
Answer:
Agar D < 0 ho to equation ke koi real roots nahi honge. Roots imaginary (complex) honge.

✅ 6. Photosynthesis kya hai?Answer:Photosynthesis wo process hai jisme green plants sunlight ki madad se carbon dioxide aur water se glucose banate hain aur oxygen release karte hain.

✅ 7. Aerobic aur Anaerobic respiration me antar likhiye.

Answers

Aerobic Respiration	Anaerobic Respiration
Oxygen ki presence me hota hai	Oxygen ke bina hota hai
Zyada energy deta hai	Kam energy deta hai
End product: CO₂ + H₂O	End product: Alcohol/Lactic acid

✅ 8. Oxidation aur Reduction kya hote hain?
Answer:
Oxidation: Oxygen ka judna ya hydrogen ka hatna.
Reduction: Oxygen ka hatna ya hydrogen ka judna.
✅ 9. Ek Redox reaction ka example dijiye.
Answer:

Is reaction me CuO reduce ho raha hai aur H₂ oxidize ho raha hai.

✅ 10. Heredity kya hai? Mendel ka ek niyam likhiye.
Answer:
Heredity wo prakriya hai jisme parents ke traits children me transfer hote hain.
Law of Dominance:
Jab do contrasting traits hote hain to unme se ek dominant trait express hota hai aur doosra recessive chhup jata hai.

FAQ – Reflection/Refraction, Nature of Roots, Life Processes, Redox Reactions, Heredity

Q1. Reflection aur Refraction me basic difference kya hai?
Answer:
Reflection me light kisi surface se takra kar wapas usi medium me laut jaati hai, jabki Refraction me light ek medium se dusre medium me jaakar apni direction change kar leti hai.
Q2. Refractive index kya batata hai?
Answer:
Refractive index batata hai ki kisi medium me light ki speed vacuum ke mukable kitni kam ho jaati hai. Jitna zyada refractive index, utni zyada bending of light.

Q3. Nature of Roots kaise determine karte hain?
Answer:
Quadratic equation ke discriminant � se roots ki nature pata chalti hai.
D > 0 → Do real aur distinct roots
D = 0 → Do equal real roots
D < 0 → Koi real root nahi
Q4. Life Processes ka main purpose kya hai?
Answer:
Life processes ka main purpose organism ko zinda rakhna hai. Nutrition, respiration, transportation aur excretion milkar body ko energy dete hain aur waste remove karte hain.

Q5. Photosynthesis kyun important hai?
Answer:
Photosynthesis earth par life ka base hai. Is process se plants food banate hain aur oxygen release karte hain, jo sabhi jeevon ke liye zaroori hai.
Q6. Redox reaction ka real life example kya hai?
Answer:
Iron ka rusting hona ek common redox reaction hai. Isme iron oxidize hota hai jab oxygen aur moisture ke contact me aata hai.

Q7. Oxidising agent aur Reducing agent me kya antar hai?
Answer:
Oxidising agent dusre substance ko oxidize karta hai aur khud reduce hota hai.
Reducing agent dusre substance ko reduce karta hai aur khud oxidize hota hai.
Q8. Heredity aur Variation me kya difference hai?
Answer:
Heredity traits ka parents se offspring me transfer hai, jabki Variation traits me difference ko darshata hai jo individuals ko unique banata hai.

Q9. Mendel ke experiments kis plant par hue the?
Answer:
Mendel ne apne experiments pea plant (Pisum sativum) par kiye the.
Q10. Board exam me in topics se kitne marks ke questions aate hain?
Answer:
Reflection/Refraction, Nature of Roots, Life Processes, Redox Reactions, Heredity se milakar lagbhag 15–20 marks tak ke questions board exam me aa sakte hain, including theory, numericals aur short answers.