The centre of the lens is its
Principal axis
Principal focus
Optic centre
Focal length
A diverging lens has
A real principal focus
A virtual principal focus
No principal focus
A principal focus same as a converging lens
When a ray of light enters an optically denser medium it
Bend towards the normal
Bend away from the normal
Pass parallel to the normal
Never bends
What happens when a parallel beam of light fall on a plane mirror or on a perfectly polished surface?
Regular reflection occurs
Diffuse reflection occurs
Total internal reflection occurs
Refraction occurs
When a person sees near objects clearly but distant objects appear blurred , then he has
Long sightedness
Short sightedness
Night blindness
Cataract
If a converging lens is fatter(more curved) then
shorter its focal length and more it magnifies
longer its focal length and more it magnifies
longer its focal length and less it magnifies
The shorter its focal length and less it magnifies.
Long sightedness can be corrected by using a
Diverging spectacle lens
Converging spectacle lens
Concave mirror
Convex mirror
The image which can be produced on a screen is called
Virtual image
Real image
Laterally invented image
Diminished image
The image which cannot be formed on a screen called
Laterally invited image
When sunlight falls on a triangular glass prism
A spectrum is obtained
Dispersion takes place
The prism separates the white light into many colours
All are true