In young's double slit experiment using monochromatic light of wavelength $\mathrm{\lambda }$. The intensity of light at a point on the screen with path difference $\mathrm{\lambda }$ is M unit. The intensity of light at a point where path difference is $\mathrm{\lambda }$/3 is :-

1. M/2

2. M/4

3. M/8

4. M/8

Yellow light of wavelength 6000 $\stackrel{\circ }{\mathrm{A}}$ produces fringes of width 0.8 mm in young's double slit experiment. If the source is replaced by another monochromatic source of wavelength 7500 $\stackrel{\circ }{\mathrm{A}}$ and the seperation between the slits is doubled then the fringe width becomes :-

1. 0.1 mm

2. 0.5 mm

3. 4.3 mm

4. 1 mm

In young's double slit experiment the distance between the slits S₁ and S₂ is 1 mm. What should be the width of each slit be so as to obtain 10 maxima of the double slit pattern within the central maximum of the single slit pattern?

1. 0.9 mm

2. 0.8 mm

3. 0.2 mm

4. 0.6 mm

The intensity of the maxima and minima in an interference pattern produced by two coherent sources of light 9: 1 . The intensities of the used light sources are in ratio :-

1. 3: 1

2. 4: 1

3. 9: 1

4. 10: 1

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