Condition for Observable Pattern

Q. What causes chromatic aberration?

1. Variation of focal length of lens with colour
2. Marginal rays
3. Central rays
4. Difference in radii of curvature of its surfaces

Q. Sources 1 and 2 emit lights of different wavelengths whereas 3 and 4 emit lights of different intensities (but same wavelength). Coherence-

1. Can be obtained by using sources 1 and 2
2. Can be obtained by using sources 3 and 4
3. Since contrast suffers when sources 3 and 4 are used so coherence cannot be obtained by using sources 3 and 4
   
4. Cannot be obtained by any of these sources

Q. If the monochromatic light is replaced by white light in the double slit experiment, what will happen?

1. No change
2. No fringes are formed
3. White and dark fringes are only formed
4. A few coloured fringes are found on either side of central white fringe

Q.

Two coherent sources of light can be obtained by

[MH CET 2001]

1. None of the above

2. Two different lamps but of the same power

3. Two different lamps

4. Two different lamps of same power and having the same colour

Q. Sources 1 and 2 emit lights of different wavelengths whereas 3 and 4 emit lights of different intensities (but same wavelength). Coherence-

1. Can be obtained by using sources 1 and 2.
2. Can be obtained by using sources 3 and 4.
3. Cannot be obtained by any of these sources.
4. Since contrast suffers when sources 3 and 4 are used so coherence cannot be obtained by using sources 3 and 4.

Q. What will be the effect on interference fringes if red light is replaced by blue light?