Q.1
What is a Spectrum?
  • A band of 7 colors
  • A group of 10 colors
  • A band of 10 colors
  • A mixture of 7 colors
Q.2
What is the spectrum?
  • A disturbance that transfers energy from place to place
  • The ability to do work
  • What we see when specific light reflects off of an object
  • The range of visible color
Q.3
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
Q.4
Rainbow is formed due to
  • Natural dispersion
  • Sunlight passing through raindrops
  • Refraction of light
  • All of the above
Q.5
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.
Q.6
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.
Q.7
A reflection of sound
  • reflection
  • refraction
  • dispersion
  • echo
Q.8
Why don't planets twinkle ?
  • They are very close to us
  • They twinkle but we cannot see
  • They are very large objects
  • They are continuosly revolving around sun
Q.9
At what position of the object does a convex lens act as a magnifying glass?
  • between F and 2F
  • between F and O
  • beyond F
  • beyond 2F
Q.10
Why do stars twinkle ?
  • Stars do not really twinkle, they just appear to twinkle when seen from the surface
  • so you can see at night
  • so the sky looks nice
  • so you can see constellations
Q.11
Which of the following is NOT a source of light?
  • eyes
  • lit candle
  • sun
  • firefly
Q.12
Myopia is corrected by using spectacles with
  • convex lenses.
  • concave lenses.
  • glass slabs.
  • prisms.
Q.13
Which colour scatters the most?
  • Red
  • Green
  • Blue
  • Yellow
Q.14
When white light enters a prism, it gets split into its constituent colours. This is due to
  • different refractive index for different wavelength of each colour
  • each colours has same velocity in the prism.
  • prism material have high density.
  • Scattering of light
Q.15
Why does scattering of light occur?
  • Light rays are blocked and reflected to all directions by the clouds or particles in the air
  • Light rays are blocked and reflracted to all directions by the clouds or particles in the air
  • Light rays are passing through and refracted to all directions by the clouds or particles in the air
Q.16
Refraction of light by the earth’s atmosphere due to variation in air density is called
  • atmospheric reflection
  • atmospheric dispersion
  • atmospheric scattering
  • atmospheric refraction
Q.17
What is the relation between angle of incidence and angle of refraction when light goes from optically rarer to denser
  • Angle I is equal to angle r
  • Angle I is greater than angle r
  • Angle I is less than angle r
  • No relation between these angles
Q.18
The splitting of white light into its constituent colours is called
  • refraction.
  • dispersion.
  • deviation.
  • displacement.
Q.19
Light has the lowest velocity in which medium?flint glass n=1.70barium glass n=1.60crown glass n=1.523water n=1.33diamond n=2.45
  • diamond
  • water
  • flint glass
  • barium glass
Q.20
Why does an apple appear red?
  • All colors are absorbed & none are reflected
  • All colors are absorbed except for blue, which is reflected
  • All colors are reflected and none are absorbed
  • All colors are absorbed except for red, which is reflected
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