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.
4. 6.5
In Young's double-slit experiment using the light of wavelength '', 60 fringes are seen on a screen. If the wavelength of light is decreased by 50%, then the number of fringes on the same screen will be:
1. 30
2. 60
3. 120
4. 90
If the polarising angle for a material is , then the refractive index of the material will be:
1.
2.
3.
4.
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 5th polaroid is:
1.
2.
3.
4.
In Y.D.S.E., the ratio of maximum intensity at a point to the intensity at the same point when one slit is closed, is:
1. 2
2. 3
3. 4
4. 1
Two light sources are said to be coherent when their:
1. | amplitudes are equal and have a constant phase difference. |
2. | wavelengths are equal. |
3. | intensities are equal. |
4. | frequencies are equal and have a constant phase difference. |
Which statement is true for interference?
1. | Two independent sources of light can produce interference pattern. |
2. | There is no violation of conservation of energy. |
3. | White light cannot produce interference. |
4. | The interference pattern can be obtained even if coherent sources are widely apart. |
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 and 2 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
In Young's double-slit experiment sources of equal intensities are used. The distance between the slits is d and the wavelength of light used is (<<d). The angular separation of nearest points on either side of central maximum where intensities become half of the maximum value is:
1.
2.
3.
4.
Four coherent sources of intensity \(I\) are superimposed constructively at a point. The intensity at that point is:
1. \(4I\)
2. \(8I\)
3. \(16I\)
4. \(24I\)