A double convex lens of focal length 30cm is made of glass. When it is immersed in a liquid of refractive index 1,4 the focal length is found to be 126cm. The critical angle between glass and the liquid is

A double convex lens of focal length 30cm is made of glass. When it is

1.	A double convex lens of focal length 30cm is made of glass. When it is immersed in a liquid of refractive index 1,4 the focal length is found to be 126cm. The critical angle between glass and the liquid is
Answer» `sin^-1(3/4)` `sin^-1(4/5)` `sin^-1(7/13)` `sin^-1(7/8)` ANSWER :D