Ray Optics and Optical Instruments - Result Question 53
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55. A thin prism having refracting angle $10^{\circ}$ is made of glass of refractive index 1.42. This prism is combined with another thin prism of glass of refractive index 1.7. This combination produces dispersion without deviation. The refracting angle of second prism should be
======= ####55. A thin prism having refracting angle $10^{\circ}$ is made of glass of refractive index 1.42. This prism is combined with another thin prism of glass of refractive index 1.7. This combination produces dispersion without deviation. The refracting angle of second prism should be
3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/ray-optics-and-optical-instruments/ray-optics-and-optical-instruments—result-question-53.md (a) $6^{\circ}$
(c) $10^{\circ}$
(b) $8^{\circ}$
(d) $4^{\circ}$
[2017]
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Answer:
Correct Answer: 55. (a)
Solution:
- (a) For dispersion without deviation
$(\mu-1) A_1+(\mu^{\prime}-1) A_2=0$
$|(\mu-1) A_1|=|(\mu^{\prime}-1) A_2|$
$(1.42-1) \times 10^{\circ}=(1.7-1) A_2$
$4.2=0.7 A_2$
$A_2=6^{\circ}$
In case of deviation without dispersion
$ \frac{A^{\prime}}{A^{\prime}}=\frac{(\mu_V-\mu_R)}{(\mu_V^{\prime}-\mu_R^{\prime})} $
