Ray Optics and Optical Instruments - Result Question 16

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16. An air bubble in a glass slab $(\mu=1.5)$ is $5 cm$ deep when viewed from one face and $2 cm$ deep when viewed from the opposite face. The thickness of the slab is

======= ####16. An air bubble in a glass slab $(\mu=1.5)$ is $5 cm$ deep when viewed from one face and $2 cm$ deep when viewed from the opposite face. The thickness of the slab is

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/ray-optics-and-optical-instruments/ray-optics-and-optical-instruments—result-question-16.md (a) $7.5 cm$

(b) $10.5 cm$

(c) $7 cm$

(d) $10 cm$

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Answer:

Correct Answer: 16. (b)

Solution:

(b) $1.5=\frac{\text{ Real depth }(R_1)}{\text{ Apparent depth }(5 cm)}$

$\therefore R_1=1.5 \times 5=7.5 cm$

For opposite face,

$1.5=\frac{R_2}{2} \Rightarrow R_2=3.0 cm$

$\therefore$ Thickness of the slab $=R_1+R_2$

$ =7.5+3=10.5 cm $

If object and observer are situated in different medium then due to refraction, object appears to be displaced

Refractive index, $\mu=\frac{\text{ Real depth }(h)}{Apparent depth(h^{\prime})}$

Real depth > Apparent depth

In case object is in rarer medium and object is in denser medium then, $\mu=\frac{h^{\prime}}{h}$

Real depth < apparent depth