engineering recuitment ISRO Scientific Assistant Physics 2020 Physics Optics Refraction and Reflection
Given below are four statements-
(p) The second principal focus of a lens is the position of the object, real or virtual whose image is at infinity.
(q) The second principal focus of a lens is the position of the image, real or virtual whose object is at infinity.
(r) The first principal focus of a lens is the position of the object, real or virtual whose image is at infinity.
(s) The first principal focus of a lens is the position of the image, real or virtual whose object is at infinity.
Examine the above statements and find which among then are correct.
1
(q) & (r)
2
(p) & (s)
3
(q) & (s)
4
(p) & (r)