two point sources s1 and s2 separated by distance 3lamda . both sources are place at distance L from the wall d<<L and are having equal intensities . find all the point on wall where light intensity will be zero .

To find the points on the wall where the light intensity will be zero, we can use the concept of interference.

1. Let's consider a point P on the wall, which is at a distance x from the point directly in front of source S1.

2. The path difference between the light waves from sources S1 and S2 at point P can be calculated using the formula: path difference = distance between S1 and P - distance between S2 and P

3. Since the sources S1 and S2 are separated by a distance of 3λ, the distance between S1 and P is L + x, and the distance between S2 and P is L + x - 3λ.

4. The path difference can be written as: path difference = (L + x) - (L + x - 3λ) = 3λ

5. For destructive interference to occur, the path difference should be an odd multiple of half the wavelength (λ/2). Therefore, we have: 3λ = (2n + 1)(λ/2), where n is an integer.

6. Simplifying the equation, we get: 3λ = (2n + 1)(λ/2) 6 = 2n + 1 2n = 5

7. Since n should be an integer, there is no integer value of n that satisfies the equation. Therefore, there are no points on the wall where the light intensity will be zero.

In conclusion, there are no points on the wall where the light intensity will be zero.