Optics Ques 206
- The intensity of light at a distance $r$ from the axis of a long cylindrical source is inversely proportional to $r$.
$(1981,2 M)$
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Answer:
Correct Answer: 206.(True)
Solution:
- At a distance $r$ from a line source of power $P$ and length $l$, the intensity will be,
$ \begin{gathered} I=\frac{P}{S}=\frac{P}{2 \pi r l} \\ I \propto \frac{1}{r} \end{gathered} $
BETA
