Question

If the radius of curvature of a lens is 30 cm, then what is its focal length?
2x 12
In the experiment of refraction through a glass slab, the angle of incidence
should be less than 90 Why?
ence E S6 OP​

Answer 1

Answer:

if it is more than 90 degree ..it undergo internal reflection..so it came back to the same medium