Two superposing waves are represented by the following equations: 
\({\mathrm{y}_1=5 \sin 2 \pi(10 \mathrm{t}-0.1 \mathrm{x}), \mathrm{y}_2=10 \sin 2 \pi(10 \mathrm{t}-0.1 \mathrm{x}).}\)
Ratio of intensities $\frac{{\mathrm{I}}_{\max }}{{\mathrm{I}}_{\min }}$ will be:

1. 1
2. 9
3. 4
​​​​​​​4. 16

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 slit separation is doubled. This results in:

Unpolarized light of intensity 32 Wm^–2 passes through three polarizers such that the transmission axes of the first and second polarizer make an angle of 30° with each other and the transmission axis of the last polarizer is crossed with that of the first. The intensity of the final emerging light will be:

1. 32 Wm^–2

2. 3 Wm^–2

3. 8 Wm^–2

4. 4 Wm^–2

On superposition of two waves \(y_{1}=3sin\left ( \omega t-kx \right )\) and \(y_{2}=4sin\left ( \omega t-kx+\frac{\pi }{2} \right )\) at a point, the amplitude of the resulting wave will be:

1.  7

2.  5

3.  $\sqrt{7}$

4.  6.5

If the polarising angle for a material is $60°$, then the refractive index of the material will be:

1.  $\frac{1}{\sqrt{3}}$

2.  $\frac{3}{2}$

3.  $\sqrt{3}$

4.  $\frac{\sqrt{3}}{2}$

Five identical polaroids are placed coaxially with \(45^{\circ}\) angular separation between pass axes of adjacent polaroids as shown in the figure. (I₀: Intensity of unpolarized light)
          
The intensity of light, I, emerging out of the 5^th polaroid is:

1.  $\frac{{\mathrm{I}}_0}{4}$

2.  $\frac{{\mathrm{I}}_0}{8}$

3.  $\frac{{\mathrm{I}}_0}{16}$

4.  $\frac{{\mathrm{I}}_0}{32}$

Two light sources are said to be coherent when their:

Light waves of intensities \(I\) and \(9I\) interfere to produce a fringe pattern on a screen. The phase difference between the waves at point P is $\frac{3\mathrm{\pi }}{2}$ and 2$\mathrm{\pi }$ at other point Q. The ratio of intensities at P and Q is:

1.  8: 5

2.  5: 8

3.  1: 4

4.  9: 1

Two coherent sources are 0.3 mm apart. They are 1 m away from the screen. The second dark fringe is at a distance of 0.3 cm from the center. The distance of the fourth bright fringe from the centre is:

1.  0.6 cm

2.  0.8 cm

3.  1.2 cm

4.  0.12 cm