Question

4. a convex lens has radii of curvature 15 cm and 10 cm. Lens material is
having refractive index 1.6 then focal length of lens is
(a) 5cm
(c) 15cm
(b) 10cm
(d) 20cm​

Answer 1

Answer:

15

Explanation:

According to the len's maker formula,

f1=(μmμl−1)(R11−R21)f1=⎝⎜⎜⎜⎛123−1⎠⎟⎟⎟⎞(151−(−151))f1=(21)(152)∴f=15cm