The deficiency of one of the following in the diet of a person for a considerable time can lead to a disease called night blindness. This one is:
vitamin B
vitamin D
vitamin A
vitamin C
The perpendicular drawn at any point on a mirror is called:
Incident ray
Reflected ray
Normal
Image
The persistence of the eye is only for:
1/10th of a second
1/12th of a second
1/16th of a second
1/20th of a second
The change in converging power of an eye-lens is caused by the action of:
iris
ciliary muscles
optic nerve
retina
Which type of mirrors are used in telescopes for reflecting light ?
Concave mirrors
Convex mirrors
Plane mirrors
Convex lenses
Cataract is a condition of eye when :
Eyesight becomes foggy
Eye lens becomes cloudy
There is a loss of vision
All of the above
In our house, we uses which type of mirror to look at ourselves ?
Convex mirror
Concave mirror
Convex lens
Plane mirror
The part which protects the human eye is called:
Cornea
Chroid
Retina
Blind spot
A rainbow is formed as a result of
Absorption of sunlight by rain drops
Reflection of sunlight by rain drops
Dispersion of sunlight by rain drops
Separation of sunlight by rain drops
The angle between an incident ray and the plane mirror is 300. The total angle between the incident ray and the reflected ray will be:
300
600
900
1200