An observer can see through a pin hole the top end of a thin rid of height h, placed as shown in figure. The beaker height 3h and its radius h. When the beaker is filled with a liquid upto a height 2h, he can see the lower end of the rod. Find the reactive index of the liquid.

An observer can see through a pin hole the top end of a thin rid of he

1.	An observer can see through a pin hole the top end of a thin rid of height h, placed as shown in figure. The beaker height 3h and its radius h. When the beaker is filled with a liquid upto a height 2h, he can see the lower end of the rod. Find the reactive index of the liquid.
Answer» SOLUTION :`PQ=QR=2h` `THEREFORE anglei=45^@` `therefoe ST=RT=h=KM=MN` so `KS=sqrt(h^2+(2h)^2)=h sqrt5` `therefore sin r= h/(h sqrt5)=1/sqrt5` ` therefore MU= (sin i)/( sin r)= (sin 45^@)/(1//sqrt5)= sqrt(5/2)`