Wave Optics Tes...

Assertion In Young\'s double slit experiment, the fringes become indistinct if one of the slits is covered with cellophane paper.
Reason The cellophane paper decreases the wavelength of light.

Assertion The unpolarised light and polarised light can be distinguished from each other by using polaroid.
Reason A polaroid is capable of producing plane polarised beams of light.

Assertion Nicol prism is used to produce and analyse plane polarised light.
Reason Nicol prism reduces the intensity of light to zero

Assertionn In everyday life the Doppler\'s effect is observed readily for sound waves that light waves.
Reason Velocity of light is greater than that of sound

Assertion In Young\'s experiment, the fringe width for dark fringes is different from that for white fringes.
Reason In Young\'s double slit experiment the fringes are performed with a source of white light, then only black and bright fringes are observed.

Assertion Coloured spectrum is seen when we look through a muslin cloth.
Reason It is due to the diffraction of white light on passing through fine slits.

Assertion When a tiny circular obstacle is placed in the path of light from some distance, a bright spot is seen at the centre of shadow of the obstacle.
Reason Destructive interference occurs at the centre of the shadow.

Assertion Thin films such as soap bubble or a thin layer of oil on water show beautiful colours when illuminated by white light.
Reason It happens due to the interference of light reflected from the upper surface of the thin film.

Assertion Microwave communication is preferred over optical communication.
Reason Microwaves provide large number of channels and band width compared to optical signals.

Assertion Corpuscular theory fails in explaining the velocities of light in air and water.
Reason According to corpuscular theory, light should travel faster in denser medium than, in rarer medium.