Optics Ques 159
- In Young’s double-slit experiment, the two slits act as coherent sources of equal amplitude $A$ and of wavelength $\lambda$. In another experiment with the same set-up the two slits are sources of equal amplitude $A$ and wavelength $\lambda$, but are incoherent. The ratio of the intensity of light at the mid-point of the screen in the first case to that in the second case is ……
$(1986,2 M)$
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Answer:
Correct Answer: 159.$(2)$
Solution:
Formula:
- In case of YDSE, at mid-point intensity will be $I _{\max }=4 I _0$ In the second case when sources are incoherent, the intensity will be $I=I _0+I _0=2 I _0$
Therefore, the desired ratio is
$ \frac{4 I _0}{2 I _0}=2 $
Here, $I _0$ is the intensity due to one slit.
BETA
