A diffraction pattern is observed using a beam of red light. What will happen if the red light is replaced by the blue light?
1. | No change takes place. |
2. | Diffraction bands become narrower. |
3. | Diffraction bands become broader. |
4. | Diffraction pattern disappears. |
1. | The diffraction pattern is not observed on the screen in the case of electrons. |
2. | The angular width of the central maximum of the diffraction pattern will increase. |
3. | The angular width of the central maximum will decrease. |
4. | The angular width of the central maximum will remain the same. |
1. | \(\dfrac{9}{4}\) | 2. | \(\dfrac{121}{49}\) |
3. | \(\dfrac{49}{121}\) | 4. | \(\dfrac{4}{9}\) |
By Huygen's wave theory of light, we cannot explain the phenomenon of:
1. | Interference |
2. | Diffraction |
3. | Photoelectric effect |
4. | Polarisation |
Soap bubble appears coloured due to the phenomenon of:
1. Interference
2. Diffraction
3. Dispersion
4. Reflection
Which of the following statements indicates that light waves are transverse?
1. | Light waves can travel in a vacuum. |
2. | Light waves show interference. |
3. | Light waves can be polarized. |
4. | Light waves can be diffracted. |
If an interference pattern has maximum and minimum intensities in a \(36:1\) ratio, then what will be
the ratio of their amplitudes?
1. \(5:7\)
2. \(7:4\)
3. \(4:7\)
4. \(7:5\)
In Young's experiment, light of wavelength \(4000~\mathring{A}\) is used to produce bright fringes of width \(0.6\) mm, at a distance of \(2\) meters. If the whole apparatus is dipped in a liquid of refractive index \(1.5\), then fringe width will be:
1. \(0.2~\text{mm}\)
2. \(0.3~\text{mm}\)
3. \(0.4~\text{mm}\)
4. \(1.2~\text{mm}\)
In two separate set-ups of the Young's double slit experiment, fringes of equal width are observed when lights of wavelengths in the ratio \(1:2\) are used. If the ratio of the slit separation in the two cases is \(2:1\), the ratio of the distances between the plane of the slits and the screen in the two set-ups is:
1. \(4:1\)
2. \(1:1\)
3. \(1:4\)
4. \(2:1\)
The slits in Young's double-slit experiment have equal widths and the source is placed symmetrically relative to the slits. The intensity at the central fringe is \(I_0\). If one of the slits is closed, the intensity at this point will be:
1. \(I_0\)
2. \(\frac{I_0}{4}\)
3. \(\frac{I_0}{2}\)
4. \(4I_0\)