Myopia can be corrected by using
concave lenses
contact lenses
prismatic lenses
convex lenses
The sum of the reciprocals of object distance and image distance is equal to the
focal length of a mirror
reciprocal of the focal length
radius of curvature
magnification
A diverging lens is used in :
a magnifying glass
a car to see objects on rear side
spectacles for the correction of short sight
a simple camera
If R is the radius of curvature of a spherical mirror and f is its focal length,then :
R = f
R = 2f
R = f/2
R = 3f
A virtual image is one which
can be taken on a screen
cannot be taken on a screen
sometimes can be and sometimes cannot be taken on a screen
is formed only by a concave mirror
The size of the pupil of the eye is adjusted by :
cornea
ciliary muscles
optic nerve
iris
The miror used by a dentist to examine the teeth of a person is :
convex
concave
plane
both concave and convex
The ratio of the sine of the angle of incidence to the sine of angle of refraction is constant and is called
Malus's law
Snell's law
Optical density
Relative density
Linear magnification (m) produced by a rear view mirror fitted in vehicles :
is equal to one
is less than one
is more than one
can be more or less than one depending on the position of object
The defect of vision which cannot be corrected by using spectacles is :
myopia
presbyopia
cataract
hypermetropia
