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A small pin fixed on a table top is viewed from above from a distance of 50cm.By what distance would the pin appear to be raised if it is viewed from the same point through a 15cm thick glass slab held parallel to the table. mue of glass is 1.5.

Let x be the real depth

Then, the apparent depth, x' = x/?

Hence, change in the apparent depth

x – x' = 15 (1 – 1/1.5) = 5.0 cm

The change in the apparent depth does not depend upon the position of the slab.