Question

1.
1 और 1 के बीच ग्राफ खींचकर एक उत्तल लेंस की फोकस दूरी ज्ञात करें।
Find the focal length of a convex lens hy plotting​

Answer 1

Answer:

An optical bench with three uprights (central upright fixed, two outer uprights with lateral movement), a convex lens with lens holder, two optical needles, (one thin, one thick) a knitting needle and a half metre scale

Explanation:

The relation between u, v and f for a convex lens is

to-find-the-focal-length-of-a-convex-lens-by-plotting-graphs-between-u-and-v-or-between-1u-and-1v-1

where,

f = focal length of convex lens

u = distance of object needle from optical centre of the lens

v = distance of image needle from optical centre of the lens.

Note. According to sign-convention, u has negative value and v has positive value. Hence, f comes positive.