Question

three students ABC measured the focal lenght of a concave mirror using parallel rays from a distant object. all of them measured the distance between the mirror and the inveryed image on a white screen. students A B and C saw images and called the distances as f1 f2 and f3 respectevely. if the students A B C observed the sharp, blurred, and more blurred image on the screen respectively then the relation between the three measurement will be A) f1 = f2 = f3B) f1 < f2 < f3C) f1 > f2> f3

Answer 1

গণ পরিষদ ও অন্যান্য অনেক বেশি পরিচিত ছিলেন তিনি উল্লেখ করা হয়

Answer 2

(b) f1 < f2 and f3

Explanation:

Given: All the students are performing the experiment using convex lens because a convex lens is a converging lens that converges a parallel beam of light to its focus.

f1 is the image distance of Student A - He gets a sharp image. So this should be the focal length of the lens.

f2 is the image distance of Student B - He gets a blurred slightly large image. f2 > f1

f3 is the image distance of Student C - He gets a blurred slightly smaller image. f3 > f2 > f1.

So the image distance is in the order: f1 < f2 and f3.

Option B is the answer.