Correct Answer - C
From the given situation , at critical angle , `"tan"theta = ((d//2))/(h) = (5.77)/(10)`
`therefore "sin" theta_(C) = (1)/(2)`
`mu_("denser") "sin"theta_(C) = mu_("rarer") "sin" (pi//2)`
`implies 2.72 xx (1)/(2) = mu_(r) implies mu_(r) = 1.36`