Choose the correct statement(s).

Options

A. The image of sun (consider point source of light) can never be produced at center of glass sphere, (assuming the space between sphere and sun is filled with air)
B. If a lens having `mu=1.5` has focal lengh `20cm` in air,then its focal length will be `60cm` when it is immersed in water of refractive index `4/3`
C. The laws of reflection and refraction are true for all surface and pairs of media at the point of incidence
D. The thick lenses give coloured images due to dispersion of light.

Answer

A, C, D

Explanation

(A) `(mu)/(+R)=(mu-1)/(+R)` (not possible)
The higher the refractive index of the material of sphere `(mu)`, the closer one could come to fulfilling the objective.

(B) `(f_(a))/(f_(w))=((mu-m_(w))/(mu-mu_(a)))((mu_(a))/(mu_(w)))`
`=((3/2-4/3)/(3/2-1))1/((4/3))=1/6xx2xx3/4=1/4`
(C) basic (NCERT-point to ponder)
(D) basic (NCERT-point to ponder)