Question

(a)
For the same angle of incidence of 45°, the refraction angle in two
transparent media P and Q is 20° and 30° respectively. Which of
the two is optically denser and why?
(b)
Define 1 dioptre power of a lens.
(c)
Find the focal length of a lens of power + 0.5 D.​

Answer 1

Answer:

1 dioptre is the power of a lens whose focal length is 1 m........

focal length =1/p is the distance is in m or 100/f if it is in cm .......