Appeared in: 2024 (3 sets)
A point light source rests on the bottom of a bucket filled with a liquid of refractive index $\mu = 1.25$ up to height of $10\text{ cm}$. Calculate :
(a) the critical angle for liquid-air interface
(b) radius of circular light patch formed on the surface by light emerging from the source.
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Official Evaluation Steps & EL10 Insight
Given Data:
- Refractive index of the liquid ($\mu$) = $1.25 = \dfrac{5}{4}$
- Depth of the point light source ($h$) = $10\text{ cm} = 0.1\text{ m}$
- Refractive index of air ($n_{\text{air}}$) = $1$
Step 1 (Formula / Governing Law & Given Data): [½ Mark + ½ Mark]