| 1. | its wavelength and frequency both increase. |
| 2. | its wavelength increases but frequency remains unchanged. |
| 3. | its wavelength decreases but frequency remains unchanged. |
| 4. | its wavelength and frequency both decrease. |
Which of the following sources gives the best monochromatic light?
1. a candle
2. a bulb
3. a mercury tube
4. a laser
The wavefronts of light coming from a distant source of unknown shape are nearly:
1. plane
2. elliptical
3. cylindrical
4. spherical
Two sources are called coherent if they produce waves:
| 1. | of equal wavelength |
| 2. | of equal velocity |
| 3. | having same shape of wavefront |
| 4. | having a constant phase difference |
Two coherent sources of different intensities send waves which interfere. The ratio of maximum intensity to the minimum intensity is \(25.\) The intensities of the sources are in the ratio:
1. \(25:1\)
2. \(5:1\)
3. \(9:4\)
4. \(625:1\)
The slits in a Young's double-slit experiment have equal width and the source is placed symmetrically with respect 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. \(I_0/4\)
3. \(I_0/2\)
4. \(4I_0\)
Which of the following properties show that light is a transverse wave?
1. Reflection
2. Interference
3. Diffraction
4. Polarization
Light is:
| 1. | a wave phenomenon |
| 2. | a particle phenomenon |
| 3. | both particle and wave phenomenon |
| 4. | none of the above |
| I. | The central fringe will be white. |
| II. | Closest bright fringe to the central fringe will be a violet fringe. |
| III. | There will not be any dark fringe. |