A person cannot see distinctly objects kept beyond 2 m. This defect can be corrected by using lens of power
  • +0. 5 D
  • -0. 5 D
  • +0. 2 D
  • -0. 2 D
A student sitting on the last bench can read the letters written on the blackboard but is not able to read / the letters written in his textbook. Which of the following statements is correct?
  • The near point of his eyes has receded away.
  • The near point of his eyes has come closer to him.
  • The far point of his eyes has come closer to him.
  • The far point of his eyes has receded away.
A prism ABC (with BC as base) is placed in different orientations. A narrow beam of white light is incident on the prism as shown in the Figures given below. In which of the following cases, after dispersion, the third colour from the top corresponds to the colour of the sky?
  • (i)
  • (ii)
  • (iii)
  • (iv)
At noon the sun appears white as
  • light is least scattered.
  • all the colours of the white light are scattered away.
  • blue colour is scattered the most.
  • red colour is scattered the most.
Which of the following phenomena of light are involved in the formation of a rainbow?
  • Reflection, refraction and dispersion
  • Refraction, dispersion and total internal reflection
  • Refraction, dispersion and internal reflection
  • Dispersion, scattering and total internal reflection
Twinkling of stars is due to atmospheric
  • dispersion of light by water droplets
  • refraction of light by different layers of varying refractive indices
  • scattering of light by dust particles
  • internal reflection of light by clouds
The clear sky appears blue because
  • blue light gets absorbed in the atmosphere.
  • ultraviolet radiations are absorbed in the atmosphere.
  • violet and blue lights get scattered more than lights of all other colours by the atmosphere.
  • light of all other colours is scattered more than the violet and blue colour lights by the atmosphere.
Which of the following statements is correct regarding the propagation of light of different colours of white light in air?
  • Red light moves fastest.
  • Blue light moves faster than green light.
  • All the colours of the white light move with the same speed.
  • Yellow light moves with the mean speed as that of the red and the violet light.
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 scattered the least by smoke or fog.
  • is absorbed the most by smoke or fog.
  • moves fastest in air.
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
The bluish colour of water in deep sea is due to
  • the presence of algae and other plants found in water
  • reflection of sky in water
  • scattering of light
  • absorption of light by the sea
When light rays enter the eye, most of the refraction occurs at the
  • crystalline lens
  • outer surface of the cornea
  • iris
  • pupil
The focal length of the eye lens increases when eye muscles
  • are relaxed and lens becomes thinner
  • contract and lens becomes thicker
  • are relaxed and lens becomes thicker
  • contract and lens becomes thinner
Which of the following statement is correct?
  • A person with myopia can see distant objects clearly.
  • A person with hypermetropia can see nearby objects clearly.
  • A person with myopia can see nearby objects clearly.
  • A person with hypermetropia cannot see distant objects clearly.
A student traces the path of a ray through a glass prism for four different values of angle of incidence. On analysing the diagrams he is likely to conclude that the emergent ray
  • is always parallel to the incident ray.
  • is always perpendicular to the incident ray.
  • is always parallel to the refracted ray.
  • always bends at an angle to the direction of incident ray.
A student is observing the diagram showing the path of a ray of light passing through a glass prism. He would find that for all angles of incidence the ray of light bends:
  • towards the normal while entering into the prism and away from the normal while emerging out of the prism
  • away from the normal while entering into the prism and towards the normal while emerging out of the prism.
  • away from the normal while entering as well as while emerging out of the prism.
  • towards the normal while entering as well as while emerging out of the prism.
In the following diagram, the path of a ray of light passing through a glass prism is shown:
  • X, R and T
  • Y, Q and T
  • X, Q and P
  • Y, Q and P
After tracing the path of a ray of light through a glass prism a student marked the angle of incidence (∠i), angle of refraction (∠r), angle of emergence (∠e) and the angle of deviation (∠D) as shown in the diagram. The correctly marked angles are:
  • ∠i and ∠r
  • ∠i and ∠e
  • ∠i, ∠e and ∠D
  • ∠i, ∠r and ∠e
The splitting of white light into its component colours is called
  • refraction
  • reflation
  • dispersion
  • tyndall effect
Reason behind advance sunrise and delayed sunset
  • atmospheric refraction
  • total internal reflection
  • dispersion
  • reflection
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