Question 321: Wave Optics

Question

Of the two slits producing interference in Young's experiment, one is covered with glass so that light intensity passing is reduced to $50 \%$. Which of the following is correct?

Accepted Answer

Initial intensity of bright fringes, $(\sqrt{I}+\sqrt{I})^2$
Final intensity of bright fringes after covering one slit with glass sheet $=\left(\sqrt{I}+\sqrt{\frac{I}{2}}ight)^2$
Clearly, the intensity of bright fringes has decreased. For dark fringes initial intensity $=(\sqrt{I}-\sqrt{I})^2$
But, new intensity $=\left(\sqrt{I}-\frac{\sqrt{I}}{2}ight)^2 
eq 0$
Hence, intensity of dark fringes increases.

Answer

Intensity of fringes remains unaltered.

Answer

Intensity of bright fringe decreases and that of dark fringe increases.

Answer

Intensity of bright fringe increases and that of dark fringe decreases.

Answer

Intensity of both bright and dark fringes decreases.

Wave Optics

Of the two slits producing interference in Young's experiment, one is covered with glass so that light intensity passing is reduced to 50 \%. Which of the following is correct?

Choose the correct answer: