Question

The focal length of the convex lens when refractive index of material n2=5/4 kept in air n=1 equal to​

Answer 1

Answer:

The focal length of a convex lens of R. I. 1.5 is f when it is placed in air. When it is immersed in a liquid is behaves as a converging lens its focal length becomes xf(x>1)

Answer 2

Answer:

15cm

Explanation:

N2=5/4

N1=1

R1=5cm

R2=15cm

F=?

1/f=(n2-1/n1)(1-1/R1-R2)

1/f=(5/4 / 1/1 -1) (1=1/5(-15)

1/f=5×1/4×1=1)(1/5+1/15)

1/f=5-4/4(4/15)

cancel

1/15=15 cm