A diffraction pattern is obtained by using beam of red light what will happen, if red light is replaced by the blue light :-

1. Bands disappear

2. Bands become broades and farther apart

3. No change will take place

4. Diffraction bands become narrow and crowded together

A screen is placed 50 cm from a single slit which is illuminated with light of wavelength 6000 $\stackrel{\circ }{\mathrm{A}}$. If the distance between the first and third minima in the diffraction pattern is 3.0 mm. The width of the slit is :-

1. 1 x 10^-4 m

2. 2 x 10^-4 m

3. 0.5 x 10^-4 m

4. 4 x 10^-4 m

In a single slit diffraction experiment, the width of the slit is made double its original width. Then the central maximum of the diffraction pattern will become :

1. narrower and fainter

2. narrower and brighter

3. broader and fainter

4. broader and brighter

The refractive index of medium is $\sqrt{3}$. If the unpolarized light is incident on it at the polarizing angle of medium the angle of refraction is :-

1. 60^o

2. 45^o

3. 30^o

4. 10^o

In young's double slit experiment, the fringe width with light of wavelength 6000 $\stackrel{\circ }{\mathrm{A}}$ is 3 mm. The fringe width, when the wavelength of the light is changed to 4000 $\stackrel{\circ }{\mathrm{A}}$:-

1. 3 m

2. 1 mm

3. 2 mm

4. 4 mm

A double slit is illuminated by light of wavelength 6000 $\stackrel{\circ }{\mathrm{A}}$. The slits due 0.1 cm apart and the screen is place 1 m away. The angular position of the 10^th maximum is radian is :-

1. 2 x 10^-4

2. 6 x 10^-3

3. 3 x 10^-3

4. 1 x 10^-4

Unpolarized light is incident on a plane glass surface. The angle of incidence so that reflected and refracted rays are perpendicular to each other, then :-

1. ${\mathrm{tani}}_{\mathrm{\beta }}=\mathrm{\mu }/2$

2. ${\mathrm{tani}}_{\mathrm{\beta }}=\mathrm{\mu }$

3. ${\mathrm{sini}}_{\mathrm{\beta }}=\mathrm{\mu }$

4. ${\mathrm{cosi}}_{\mathrm{\beta }}=\mathrm{\mu }$

If a light wave passes through a transparent medium (like as glass). Then :-

1. Velocity of all light waves will be same

2. Velocity of longer wavelength will be less

3. Velocity of longest wavelength will be maximum

4. Velocity of shorter wavelength will be maximum

Two periodic waves of intensities I₁ and I₂ pass through a region at the same time in the same direction. The sum of the maximum and minimum intensities is :-

1. I₁ + I₂

2. ${\left(\sqrt{{\mathrm{I}}_1}+\sqrt{{\mathrm{I}}_2}\right)}^2$

3. ${\left(\sqrt{{\mathrm{I}}_1}-\sqrt{{\mathrm{I}}_2}\right)}^2$

4. 2(I₁ + I₂)

In a double slit experiment, instead of taking slits of equal widths, one slit is made twice as wide as the other. Then, in the interference pattern :-

1. the intensities of both the maxima and the minima increase

2. the intensity of the maxima increases and the minima has zero intensity

3. the intensity of the maxima decreases and that of the minima increases

4. the intensity of the maxima decreases and the minima has zero intensity