Question 355: Wave Optics

Question

Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is $$\pi / 2$$ at point $$\mathrm{A}$$ and $$\pi$$ at point $$\mathrm{B}$$. Then the difference between the resultant intensities at $$\mathrm{A}$$ and $$\mathrm{B}$$ is

Accepted Answer

$$\begin{aligned}
& \mathrm{IA}=\mathrm{I}+4 \mathrm{I}+2 \sqrt{I} \cdot \sqrt{4 I} \cdot \cos \frac{\pi}{2} \
& =5 I \
& \mathrm{I}_8=I+4 I+2 \sqrt{I} \cdot \sqrt{4 I} \cdot \cos \pi \
& =I \
& 	herefore I_A-I_B=5 I-I=4 I
\end{aligned}$$

Answer

4I

Answer

5I

Answer

2I

Answer

3I

Wave Optics

Two beams of light having intensities I and 4I interfere to produce a fringe pattern on a screen. The phase difference between the beams is $\pi / 2 at point \mathrm{A} and \pi at point \mathrm{B}. Then the difference between the resultant intensities at \mathrm{A} and \mathrm{B}$ is

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