Question

The radii of curvatures of convex lens are 24cm and 8cm. Its refractive
index is 1.5, then its focal length is​

Answer 1

Answer:

From LMF,

f

1

=(n−1)(

R

1

1

−

R

2

1

)

Since it is diverging , f=−24cm

Given that R

1

=2R

2

,n=1.5

−24

1

=(1.5−1)(

2R

2

1

−

R

2

1

)

−12

1

=

2R

2

−1

R

2

=6cm,R

1

=12cm

Explanation:

l hope it will help u

Answer 2

Explanation:

1/f = (Mu - 1) [ 1/R1 - 1/R2]

R1 = 8 cm. R2 = -24 cm using the sign convention.

My 1.5.

1/f = 0.5 × [ 1/8 - (1/-24)] = 1/12

f = 12 cm.