Q.21)-Total internal reflection can not take place when light goes from
- Water to glass
- Glass to water
- Water to air
- Glass to air
Q.22)-Optical fibre works on the principle of
- Refraction
- Scattering
- Interference
- Total internal reflection
Q.23)-Energy in reflected light is
- Does not depend on the angle of incidence
- Increases with increase in angle
- Decrease with increase in angle incidence
- Become maximum for an angle of incidence of 45 degree
Q.24)-Which of the following optical phenomena is responsible for the brilliance of diamond?
- Maximum refraction
- Total internal reflection
- Total surface reflection
- 100% transmission
Q.25)-The phenomenon of change in direction of light when it passes from one medium to another is called
- Propagation
- Reflection
- Refraciton
- Dispersion
Q.26)-which of the following is not caused by atmospheric refraction?
- Sun appearing red at sunset
- Twinkling of stars at night
- Sun appearing higher in the sky than it actually is
- Sun becoming visible two or three minutes before actual sunrise.
Q.27)-A star appears twinkling in the sky because of
- Scattering of light by atmosphere
- Reflection of light by atmosphere
- Refraction of light by atmosphere
- Diffraction of light by atmosphere
Q.28)-A water tank appears shallower when it is viewed from top due to
- Rectilinear propagation of light
- Reflection
- Total internal reflection
- Refraction
Q.29)-The reason for a swimming pool to appear less deep than the actual depth is
- Refraction
- Light scattering
- Reflection
- Interference
Q.30)-A plane glass slab is kept over coloured letters which appears leasat raised is
- Red
- Green
- Violet
- Blue
