Physics
The radius of the sphere whose part is the lens surface is called the …………… of that surface.
- centre of curvature
- focal length
- pole
- radius of curvature
Related Questions
If half part of a convex lens is covered, the focal length …………… but the intensity of the image ……………
- increases, decreases
- decreases, increases
- does not change, increases
- does not change, decreases
The focal length of a thin convex lens is …………… than that of a thick lens.
- less
- more
- same
- none of the above
Identify the incorrect statement :
- if the medium on both sides of a lens is same, its first and second focal lengths are equal, i.e. f1 = f2 (numerically).
- when we say focal length of a lens, we mean the first focal length of the lens.
- a convex lens has a real focus.
- a concave lens has a virtual focus.
What is a lens?