The relation between the fringe width for the red light and yellow light is: (all other things being the same.)

$1. {\beta }_{red}<{\beta }_{yellow}$
$2. {\beta }_{red}>{\beta }_{yellow}$
$3. {\beta }_{red}={\beta }_{yellow}$
$4. {\beta }_{red}=2{\beta }_{yellow}$

Fringe width in a particular YDSE 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

If the 5th order maxima of wavelength 4000 $\stackrel{\mathrm{o}}{\mathrm{A}}$ in Young's double-slit experiment coincides with the nth order maxima of wavelength 5000 $\stackrel{\mathrm{o}}{\mathrm{A}}$, then n is equal to:

1.  5

2.  8

3.  4

4.  10

In Young's double-slit experiment the light emitted from the source has $\lambda$ = 6.5 × 10^–7 m and the distance between the two slits is 1 mm. The distance between the screen and slits is 1 metre. Distance between third dark and fifth bright fringe will be:

1. 3.2 mm 

2. 1.63 mm 

3. 0.585 mm 

4. 2.31 mm

In Young's double-slit experiment, the separation d between the slits is 2 mm, the wavelength $\lambda$ of the light used is 5896 Å and distance D between the screen and slits is 100 cm. It is found that the angular width of the fringes is 0.20°. To increase the fringe angular width to 0.21° (with same $\lambda$ and D) the separation between the slits needs to be changed to:

1. 1.8 mm

2. 1.9 mm

3. 2.1 mm

4. 1.7 mm

In Young's double slit experiment, the angular width of fringe is 0.20^o for sodium light of wavelength 5890 Å.  The angular width of fringe, if the complete system is dipped in water, will be:

1. 0.11^o

2. 0.15^o

3. 0.22^o

4. 0.30^o

Two slits in Young's experiment have widths in the ratio of 1: 25. The ratio of intensity at the maxima and minima in the interference pattern I_max/I_min is:
1. 9/4
2. 121/49
3. 49/121
4. 4/9

In Young's experiment, light of wavelength 4000 Å is used to produce bright fringes of width 0.6 mm, at a distance of 2 meters. If the whole apparatus is dipped in a liquid of refractive index 1.5, then fringe width will be:

1. 0.2 mm

2. 0.3 mm

3. 0.4 mm

4. 1.2 mm

Young's double-slit experiment is performed in a liquid. The 10^th bright fringe in the liquid lies where the 8th dark fringe lies in a vacuum. Refractive index of the liquid is approximately:

1.  1.81

2.  1.67

3.  1.54

4.  1.33