JAMB Physics 2010 Paper

Concept:Apparent depth is the depth perceived by an observer when light travels from a denser medium to a less dense medium.Explanation:The refractive index of a medium relates the real depth and the apparent depth by the formula:$n = \frac{\text{real depth}}{\text{apparent depth}}$For the ice block, the real depth is given as $10\ \text{cm}$ and the refractive index is $n = 1.50$.Let the apparent depth be $d$.Substituting into the formula gives:$1.50 = \frac{10}{d}$Rearranging for $d$:$d = \frac{10}{1.50}$$d = 6.67\ \text{cm}$Therefore, the object appears to be at a depth of $6.67\ \text{cm}$ below the surface.Answer:$6.67\ \text{cm}$ (Option B).