The distance between the pole and the principal focus is called,
Radius of curvature
Principle axis
Aperture
Focal length
Wood is an example of
opaque object
transparent object
translucent object
non-luminous objects
When a beam consists of light rays traveling parallel to each other, then such a beam of light is called
parallel beam of light
divergent beam of light
convergent beam of light
perpendicular beam of light
A solar eclipse occur only on a
new moon day
full moon day
gibbous moon
half moon
Rays of light always travel in a straight line.This phenomenon is called
Total internal reflection
Rectilinear propogation
Scattering of light
Diffraction
An observer in the umbra experiences a:
Partial solar eclipse
Total solar eclipse
Partial lunar eclipse
None of these
The darkest part of the shadow is:
Penumbra
Antumbra
Umbra
Concave mirror act as
Plane mirror
Cylindrical mirror
Converging mirror
Convex mirror
In spherical mirror, P is denoted by
Principle focus
Pole
Principal axis
Plane
