IF Young's experiment is performed using two separate identical sources of light instead of using two slits and one light source then the

Options

A. Interference fringes will be darker
B. Interference fringes will be higher
C. Fringes will not be obtained
D. Constrast between bright and dark fringes increases

Answer

To solve the question regarding Young's experiment with two separate identical sources of light, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Young's Experiment**:
Young's double-slit experiment typically involves a single coherent light source illuminating two closely spaced slits, which then produce an interference pattern on a screen due to the superposition of light waves.

**Hint**: Recall the definition of coherent sources and their role in producing interference patterns.

2. **Identifying the Change**:
In this scenario, we are replacing the single light source and two slits with two separate identical sources of light. The key point here is that these sources are separate.

**Hint**: Consider how the coherence of the light sources affects the interference pattern.

3. **Coherence of the Sources**:
For interference to occur, the light sources must be coherent, meaning they should have a constant phase relationship. Identical sources may not necessarily be coherent if they are separate, as they can emit light waves with different phases.

**Hint**: Think about what happens when two sources are not in phase with each other.

4. **Resulting Interference**:
Since the two separate sources are not guaranteed to maintain a constant phase difference, they can be classified as incoherent sources. Incoherent sources do not produce a stable interference pattern, as the phase relationship between the waves can vary randomly.

**Hint**: Reflect on the conditions required for sustained interference patterns.

5. **Conclusion**:
Because the sources are incoherent, there will be no observable interference fringes on the screen. The light waves from the two sources will superpose, but they will not create a defined pattern of bright and dark fringes.

**Hint**: Summarize the implications of using incoherent sources in terms of interference.

### Final Answer:
Therefore, if Young's experiment is performed using two separate identical sources of light instead of using two slits and one light source, **no interference fringes will be obtained** due to the incoherence of the sources.