Question

a biconvex lens has a radius of curvature 20cm each if the refractive index of the material of the lens is 1.5 its focal length is

Answer 1

In biconvex lens, radius of curvature, R1=20 cm .if one side is take as positive ,so the other side is taken as negative , R2=-20cm
Refractive index, n=1.5 Focal length, f=?
By using the formula ,, 1/f=(n-1)[(1/R1) -(1/R2)]
1/f=1.5–1 [(1/20) — (—1/20)
1/f= 0.5 [2/20] 1/f=0.5(1/10)
f=10/0.5
f=20 cm .

Answer 2

Answer:

accha lage toh like krne ka