An extended object of size `2cm` is placed at a distance of `10cm` in air `(n = 1)` form pole, on the other side of refracting surface has refractive index `n = 2`. Find the positon, nature and size of image formed after single refraction through the curved surface.

Answer

`40 cm` form pole in the medium of refractive index `1`, virtual erect and `4cm` in size.

Explanation

For refraction at spherical surface
`(mu_(2))/(v) - (mu_(1))/(u) = (mu_(2) - mu_(1))/(R) rArr (2)/(V) - (1)/(-10) = (2-1)/(+20)`
`rArr (2)/(v) + (1)/(10) = (1)/(20) rArr (2)/(V) = -(1)/(20) rArr v = -40cm`. (virtual)
Using magnification formula.
`m = (h_(2))/(h_(1)) = + ((mu_(1))/(mu_(2)))((v)/(u)) rArr (h_(2))/(2) = (1xx(-40))/(2xx(-10)) rArr h_(2) = +4cm` (erect)