A beaker is placed on the top of a coin. The top of the beaker is closed with an opaque body with a small hole. View the coin from an angle , slowly add water through the hole while continuing to view the coin from the same angle. Repeat the procedure using cooking oil.
a. What happens when water is continuously added ?
b. What about the heights of water and oil, when con completely disappears ?
c. In which liquid, the coin is concealed best with minimum height? Why?
d. What is the valation between opitieal angle and refrective index. ?

Explanation

Coin appears to be raised.
b. Height of the oil is less than that of water.
c. Since the critical angle of oil is less than that of water, object disappears more earily in oil
d. `n = (1)/(sini_(e))`