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. \(24I\)
Two waves, each of intensity \(i_{0}\)
1. \(2i_{0}\)
2. \(i_{0}\)
3. \(i_{0}/2\)
4. zero
If the 5th order maxima of wavelength 4000 in Young's double-slit experiment coincides with the nth order maxima of wavelength 5000 , then n is equal to:
1. 5
2. 8
3. 4
4. 10
Young's double-slit experiment is performed in a liquid. The 10th 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
If the ratio of amplitudes of two coherent sources producing an interference pattern is 3 : 4, the ratio of intensities at maxima and minima is:
1. 3 : 4
2. 9 : 16
3. 49 : 1
4. 25 : 7
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