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 nonuniform

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 wave theory of light?

(a) Light obeys laws of reflection.

(b) Speed of light in water is smaller than the speed in vacuum.

(c) Light shows interference.

(d) Light shows photoelectric effect.

Choose the correct option:

1. (a) and (b)

2. (b) and (c)

3. (c) and (d)

4. All of these

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. \(x+y+z=c\)

If the source of light used in a Young's double-slit experiment is changed from red to violet,