alleryX is denser by mass, but nX=1.2 and nY=1.5. Light is slower in
AX, from its greater mass density
BBoth at identical speeds
CY, from its higher optical index
DX, from its lower optical index
Answer & Solution
Correct answer: C. Y, from its higher optical index
Light speed follows refractive index rather than mass density, so it is slower in higher-index Y.
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