Class 10 Science Chapter 9 | Part - 4 | Convex Mirror + Mirror Formula 🔥 NCERT Questions | Faiz Sir

🔥 Class 10 Science NCERT Chapter 9 – Light: Reflection and Refraction (Part 4) Welcome to Infinix Classes by Faiz Sir. In this important lecture of Class 10 Science Chapter 9, we discuss Image Formation by Convex Mirror, Uses of Convex Mirror, Mirror Formula, New Cartesian Sign Convention, and Important NCERT Questions with Detailed Solutions. यह वीडियो Class 10 Science बोर्ड परीक्षा के लिए बहुत महत्वपूर्ण है क्योंकि इसमें Mirror Formula, Convex Mirror Image Formation, Sign Convention और NCERT Book Questions को विस्तार से समझाया गया है। 📚 Topics Covered in This Lecture 🪞 Image Formation by Convex Mirror (उत्तल दर्पण द्वारा प्रतिबिंब निर्माण) 1️⃣ Object at Infinity (अनंत पर) ✔ Image at Focus (F) ✔ Virtual and Erect ✔ Highly Diminished ✔ Behind the Mirror 2️⃣ Object Between Infinity and Pole (P) ✔ Image Between Pole and Focus ✔ Virtual and Erect ✔ Diminished ✔ Behind the Mirror 🚘 Uses of Convex Mirror (उत्तल दर्पण के उपयोग) ✅ Rear View Mirror in Vehicles ✅ Traffic Safety Mirrors ✅ Security Mirrors in Shops ✅ Wide Field of View Applications 📐 Mirror Formula for Spherical Mirrors Formula: 1/f = 1/v + 1/u Where: u = Object Distance v = Image Distance f = Focal Length 📏 New Cartesian Sign Convention ✔ Pole is taken as Origin ✔ Right Side (+ Positive) ✔ Left Side (− Negative) ✔ Above Principal Axis (+ Positive) ✔ Below Principal Axis (− Negative) Sign Convention for Mirrors: Concave Mirror → f = Negative Convex Mirror → f = Positive 📝 NCERT Important Questions Discussed Q1. Define Principal Focus of Concave Mirror मुख्य फोकस की परिभाषा Q2. Radius of Curvature = 20 cm, Find Focal Length Formula Used: R = 2f f = R/2 = 10 cm Q3. Which Mirror Forms Erect and Enlarged Image? Answer → Concave Mirror Q4. Why Convex Mirror is Used as Rear View Mirror? Answer: ✔ Wider Field of View ✔ Virtual Image ✔ Erect Image ✔ Diminished Image 🎯 Important For ✅ CBSE Class 10 Board Exam ✅ NCERT Science Chapter 9 ✅ School Exams ✅ Unit Test ✅ Half-Yearly Examination ✅ Annual Examination ✅ Numerical Questions ✅ Physics Concept Building 👨‍🏫 Teacher Faiz Sir (M.Sc. Maths with CS) 🏫 Channel Infinix Classes Complete NCERT Coverage | Easy Explanation | Board Exam Preparation 👍 Like | Share | Subscribe 🔔 Subscribe Infinix Classes for Maths and Science preparation. Class 10 Science Chapter 9, Convex Mirror, Mirror Formula, New Cartesian Sign Convention, Light Reflection and Refraction, NCERT Questions, Physics Class 10, CBSE Board Exam 2026, Reflection of Light, Spherical Mirrors, Mirror Formula Numericals #class10science #lightreflectionandrefraction #convexmirror #mirrorformula #CartesianSignConvention #ncertquestions #physicsclass10th #reflectionoflight #class10physics #cbseboardexam #boardexam2026 #scienceclass10 #faizsir #infinixclasses #ncertscience class 10 science chapter 9, light reflection and refraction class 10, convex mirror class 10, image formation by convex mirror, convex mirror uses class 10, mirror formula class 10, spherical mirrors class 10, new cartesian sign convention class 10, reflection of light class 10, class 10 physics chapter 9, ncert science class 10 chapter 9, cbse class 10 science, board exam class 10 physics, mirror formula numericals class 10, radius of curvature questions class 10, principal focus class 10, convex mirror rear view mirror, image formation by mirrors class 10, physics class 10 ncert, light chapter class 10 science, light reflection and refraction faiz sir, infinix classes by faiz sir, उत्तल दर्पण, दर्पण सूत्र, नया कार्तीय चिह्न परिपाटी, प्रकाश परावर्तन तथा अपवर्तन, कक्षा 10 विज्ञान अध्याय 9, उत्तल दर्पण द्वारा प्रतिबिंब निर्माण, एनसीईआरटी प्रश्न class 10 science QUESTIONS सवाल 1. Define the principal focus of a concave mirror. Ans : Light rays that are parallel to the principal axis of a concave mirror converge at a specific point on its principal axis after reflecting from the mirror. This point is called the principal focus of the concave mirror. 2. The radius of curvature of a spherical mirror is 20 cm. What is its focal length? Ans : Radius of curvature (R) = 20 cm Radius of curvature of the spherical mirror = 2 × Focal length (f) R = 2f f= R/2 = 20 / 2 = 10 Therefore, the focal length of the spherical mirror is 10 cm. 3. Name a mirror that can give an erect and enlarged image of an object. उस दर्पण का नाम बताइए जो किसी वस्तु का सीधा और बड़ा प्रतिबिंब बना सकता है। Ans : The mirror that can give an erect and enlarged image of an object is a Concave Mirror. 4. Why do we prefer a convex mirror as a rear-view mirror in vehicles? हम गाड़ियों में रियर-व्यू मिरर के तौर पर उत्तल दर्पण (convex mirror) को क्यों पसंद करते हैं? Ans : A convex mirror is preferred as a rear-view mirror in cars and vehicles as it gives a wider field of view, which helps the driver see most of the traffic behind him. Convex mirrors always form an erect, virtual, and diminished image of the objects placed in front of it.