A coin is placed in an empty beaker. When a transparent liquid is poured into the beaker, the apparent depth of the coin is found to be 40% less than the real depth. What is the refractive index of the liquid? The options for the answer are 0.4 / 0.6 / 1.2 / 1.7

D. 1.7

Explanation:

Refractive index can be calculated using the formula;

η =real depth/apparent depth

Assume the real depth to bex

Apparent depth will be : 40% less than real depth;

60/100 *x =0.6x

η = x/ 0.6 x

η = 1/0.6

η= 10/6

η = 1.66

η = 1.7

i think the answer would be b