In double slit experiment the angular width of a fringe is found to be 0.2^o on a screen placed 1 m away. The wavelength of light used is 600 nm. The angular width of the fringe if entire experimental apparatus is immersed in water is $\left({\mathrm{\mu }}_{\text{water }}=\frac{4}{3}\right)$ :-

1. 0.15^o

2. 1^o

3. 2^o

4. 0.3^o

In young's double slit experiment distance between two sources is 0.1 mm. The distance of screen from the source of 20 cm. Wavelength of light used is 5460 $\stackrel{\circ }{\mathrm{A}}$. Then, angular position of the first dark fringe is :-

1. 0.08^o

2. 0.16^o

3. 0.20^o

4. 0.31^o

A parallel beam of light of wavelength 500 nm falls on a narrow slit and the resulting diffraction pattern is observed on a screen 1 m away. It is observed that the first minima is at a distance of 2.5 mm from the centre of the screen. The width of the slit is :-

1. 0.2 mm

2. 1 mm

3. 2 mm

4. 1.5 mm

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