Wave Optics - Result Question 17
17. In Young’s double slit experiment the distance between the slits and the screen is doubled. The separation between the slits is reduced to half. As a result the fringe width [NEET Kar: 2013]
(a) is doubled
(b) is halved
(c) becomes four times
(d) remains unchanged
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Answer:
Correct Answer: 17. (c)
Solution:
- (c) Fringe width $\beta=\frac{\lambda D}{d}$;
From question $D^{\prime}=2 D$ and $d^{\prime}=\frac{d}{2}$
$\therefore \beta^{\prime}=\frac{\lambda D^{\prime}}{d^{\prime}}=4 \beta$
