Two coherent sources of light interfere and produce fringe patterns on a screen. For the central maximum, the phase difference between the two waves will be: 

1.	zero	2.	\(\pi\)
3.	\(\dfrac{3\pi}{2}\)	4.	\(\dfrac{\pi}{2}\)

Two slits are made one millimetre apart and the screen is placed one metre away. What should the width of each slit be to obtain \(10\) maxima of the double-slit pattern within the central maximum of the single-slit pattern?
1. \(2~\text{mm}\)
2. \(0.2~\text{mm}\)
3. \(0.02~\text{mm}\)
4. \(20~\text{mm}\)

A plane-polarized light with intensity \(I_0\) is incident on a polaroid with an electric field vector making an angle of \(60^{\circ}\) with the transmission axis of the polaroid. The intensity of the resulting light will be:

The first diffraction minima due to a single slit diffraction is at \(\theta = 30^{\circ}\) for a light of wavelength  \(5000~\mathring {A}.\)  The width of the slit is:
1. \(5\times 10^{-5}~\text{cm}\)
2. \(10\times 10^{-5}~\text{cm}\)
3. \(2.5\times 10^{-5}~\text{cm}\)
4. \(1.25\times 10^{-5}~\text{cm}\)

Fringe width in a particular Young's double-slit experiment is measured to be \(\beta.\) What will be the fringe width if the wavelength of the light is doubled, the separation between the slits is halved and the separation between the screen and slits is tripled?
1. \(10\) times
2. \(11\) times
3. Same
4. \(12\) times

The relation between the fringe width for the red light and yellow light is:
(all other things being the same.)
1. \(\beta_\text{red} < \beta_\text{yellow}\)
2. \(\beta_\text{red} > \beta_\text{yellow}\)
3. \(\beta_\text{red} = \beta_\text{yellow}\)
4. \(\beta_\text{red} =2 \beta_\text{yellow}\)

If the light is polarised by reflection, then the angle between reflected and refracted light is:

When the light diverges from a point source, the shape of the wavefront is:
1. Parabolic
2. Plane
3. Spherical
4. Elliptical

In Young’s double-slit experiment using monochromatic light of wavelength \(\lambda,\) the intensity of light at a point on the screen where path difference \(\lambda\) is \(K\) units. What is the intensity of the light at a point where path difference is \(\lambda/3\)?
1. \(\dfrac K3\)
2. \(\dfrac K4\)
3. \(\dfrac K2\)
4. \(K\)

The wavefronts of a light wave travelling in vacuum are given by \(x+y+z=c\). The angle made by the direction of propagation of light with the X-axis is:
1. \(0^{\circ}\)
2. \(45^{\circ}\)
3. \(90^{\circ}\)
4. \({\cos^{-1}\left({1}/{\sqrt{3}}\right )}\)