I is the intensity due to a source of light at any point P on the screen.Now the light reaches at P via two different paths (i) direct (ii) after reflection from a plane mirror.If the path difference between two paths is 3lambda//2, the intensity at P is :

I is the intensity due to a source of light at any point P on the scre

1.	I is the intensity due to a source of light at any point P on the screen.Now the light reaches at P via two different paths (i) direct (ii) after reflection from a plane mirror.If the path difference between two paths is 3lambda//2, the intensity at P is :
Answer» zero I 2I 4I Solution :Whenever light is reflected from a plane mirror, an additionla path difference of `(LAMBDA)/(2)` between two WAVES is introduced. `THEREFORE` Total path difference `= (3 lambda)/(2) + (lambda)/(2) = 2 lambda` This SATISFIES the condition of maxima. Hence the total intensity `infty (a + a)^(2)` `infty 4a^(2) = 4I`.

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I is the intensity due to a source of light at any point P on the screen.Now the light reaches at P via two different paths (i) direct (ii) after reflection from a plane mirror.If the path difference between two paths is 3lambda//2, the intensity at P is :

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