For distinct interference pattern to be observed, the necessary condition is that the ratio of intensity of light emission by both the sources should be:

• (A) 2:1
• (B) 1:2
• (C) 1:1
• (D) 1:4

To observe a distinct interference pattern, the intensity ratio of light emitted by the two sources must be equal. This means that the correct answer is:

Answer

(C) 1:1

Explanation

When the intensities are equal, constructive and destructive interference occurs more clearly, allowing for a noticeable pattern. If the intensities differ significantly, the pattern may become less distinct.

Key Points

• Equal intensity leads to clear interference patterns.
• Different intensity ratios can obscure the pattern.