LIGHT AND EYE

The persistence of vision for human eye is

• 1/10th of a second

• 1/6th of the second

• 1/16th of a second

• 1/18th of a second

The amount of light entering the human eye is controlled by

• Ciliary muscles

• Pupil

• Cornea

• Iris

One cannot see through the fog, because

• refractive index of the fog is very high

• fog absorbs light

• light is scattered by the droplets

• light suffers total reflection at droplets

The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light

• is scattered the most by smoke or fog

• is absorbed the most by smoke or fog

• is scattered the least by smoke or fog

• moves fastest in air

Which of the following is a natural phenomenon which is caused by the dispersion of sunlight in the sky?

• Rainbow

• Twinkling of stars

• Advanced sunrise and delayed sunset

• Stars seem higher than they actually are

Human eye acts like a

• endoscope

• microscope

• telescope

• camera

Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?

• Dispersion of light

• Scattering of light

• Total internal reflection of light

• Reflection of light from the earth

  View Answer

The light sensitive cell present on retina and is sensitive to the intensity of light is:

• Cones

• Both rods and cones

• Rods

• none of above

what is the function of iris in the eye?

• it detect colours.

• it focuses the light.

• it controls the size of pupil.

The image formed on the retina is _____________

• upside

• upside down

• rotated at 90 degrees angle.