Huygens' wave theory allows us to know the:

When the light diverges from a point source, the shape of the wavefront is:

1. Parabolic.

2. Plane.

3. Spherical.

4. Elliptical.

By Huygen's wave theory of light, we cannot explain the phenomenon of:

Which of the following is not true?

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

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

Two sources with intensity I_o and 4I_o respectively interfere at a point in a medium. The maximum and the minimum possible intensity respectively would be:
1. 2I_o, I_o
2. 9I_o, 2I_o
3. 4I_o, I_o
4. 9I_o, I_o

Two light sources are said to be coherent when their:

In Young's double-slit experiment, the intensity of light at a point on the screen where the path difference is λ is K, (λ being the wavelength of light used). The intensity at a point where the path difference is λ/4 will be:

1. K

2. K/4

3. K/2

4. Zero

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