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 \(\frac{3\pi}{2}\) and \(2\pi\) at other point \(Q\). The ratio of intensities at \(P\) and \(Q\) is:
1. \(8:5\)
2. \(5:8\)
3. \(1:4\)
4. \(9:1\)
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 \(\lambda (\lambda<<d)\). The angular separation of nearest points on either side of central maximum where intensities become half of the maximum value is:
1. \(\frac{\lambda}{d}\)
2. \(\frac{\lambda}{2d}\)
3. \(\frac{\lambda}{4d}\)
4. \(\frac{\lambda}{6d}\)
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. \(24I\)
If the \(5\)th order maxima of wavelength \(4000~\mathring{A}\) in Young's double-slit experiment coincides with the \(n\)th order maxima of wavelength \(5000~\mathring{A},\) then \(n\) is equal to:
1. \(5\)
2. \(8\)
3. \(4\)
4. \(10\)
The resolving power of a microscope can be increased by using:
1. red light.
2. blue light.
3. oil between objective lens and object.
4. both (2) and (3).
Young's double-slit experiment is performed in a liquid. The \(10\)th bright fringe in the liquid lies where the \(8\)th dark fringe lies in a vacuum. The 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. \(0.6~\text{cm}\)
2. \(0.8~\text{cm}\)
3. \(1.2~\text{cm}\)
4. \(0.12~\text{cm}\)
Huygens' wave theory allows us to know the:
1. | Wavelength of the wave. |
2. | Velocity of the wave. |
3. | Amplitude of the wave. |
4. | Propagation of wavefront. |