{
  "quizTitle": "CBSE Class X - Light: Reflection & Refraction",
  "quizCategory": "CBSE Class X",
  "quizSubject": "Physics",
  "questions": [
    {
      "questionText": "The focal length of a spherical mirror with radius of curvature 30 cm is:",
      "options": [
        "60 cm",
        "15 cm",
        "30 cm",
        "7.5 cm"
      ],
      "correctOptionIndex": 1,
      "explanationText": "The focal length f of a spherical mirror is related to its radius of curvature R by f = R / 2. Here, f = 30 / 2 = 15 cm.",
      "hint": "Focal length is half the radius of curvature."
    },
    {
      "questionText": "Which type of mirror is preferred as a rear-view (wing) mirror in vehicles?",
      "options": [
        "Concave mirror",
        "Convex mirror",
        "Plane mirror",
        "Cylindrical mirror"
      ],
      "correctOptionIndex": 1,
      "explanationText": "Convex mirrors always give an erect, diminished virtual image and have a wider field of view because they are curved outwards.",
      "hint": "Provides a wider field of view with upright images."
    },
    {
      "questionText": "The refractive index of diamond with respect to air is 2.42. What does this indicate about the speed of light in diamond?",
      "options": [
        "Speed of light is 2.42 times faster in diamond than in air",
        "Speed of light in diamond is 1 / 2.42 times the speed of light in vacuum",
        "Light does not travel inside diamond",
        "Speed of light is invariant across diamond and vacuum"
      ],
      "correctOptionIndex": 1,
      "explanationText": "Refractive index n = c / v. An index of 2.42 means speed v = c / 2.42, which is significantly slower than in vacuum.",
      "hint": "Higher refractive index means light travels slower in that optical medium."
    },
    {
      "questionText": "What is the SI unit of power of a lens?",
      "options": [
        "Watt",
        "Dioptre",
        "Candela",
        "Lumen"
      ],
      "correctOptionIndex": 1,
      "explanationText": "The power of a lens is the reciprocal of its focal length in meters (P = 1/f). Its SI unit is the Dioptre (D).",
      "hint": "Symbolized by capital letter D."
    }
  ]
}