When a drop of oil is spread on a water surface, it displays beautiful colours in daylight because of:

1.	dispersion of light	2.	reflection of light
3.	polarization of light	4.	interference of light

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. \(4I_0\)

A thin transparent sheet is placed in front of a Young's double-slit. The fringe width will:
1. increase
2. decrease
3. remain same
4. become non-uniform

If Young's double-slit experiment is performed in water,

1. the fringe width will decrease

2. the fringe width will increase

3. the fringe width will remain unchanged

4. there will be no fringe

A light wave can travel:

Which of the following properties of light conclusively support the wave theory of light?

Choose the correct option from the given ones:

Three observers A, B and C measure the speed of light coming from a source to be V_A, V_B and V_C. The observer A moves towards the source and C moves away from the source at the same speed. The observer B stays stationary. The surrounding space is water everywhere.

(a) \(v_{A}>v_{B}>v_{C}\)

(b) \(v_{A}<v_{B}<v_{C}\)

(c) \(v_{A}=v_{B}=v_{C}\)

(d) \(v_{B}=\frac{1}{2}\left(v_{A}+v_{C}\right)\)

Choose the correct option:

1. (a) and (b)

2. (b) and (c)

3. (c) and (d)

4. (a) and (d)

Light waves travel in vacuum along the X-axis. Which of the following may represent the wavefronts?
1. \(x=c\)
2. \(y=c\)
3. \(z=c\)
4. \(x+y+z=c\)