Question

The diagram shows an equiconvex lens. What should be the condition on the refractive indices so that the lens becomes diverging?

Answer 1

`(mu_(3))/(v)-(mu_(1))/(u)=(mu_(2)-mu_(1))/(R_(1))+(mu_(3)-mu_(2))/(R_(2))`
`(mu_(3))/(v)-(mu_(1))/(oo)=(mu_(2)-mu_(1))/(R)+(mu_(3)-mu_(2))/((-R))`
`(mu_(3))/(v)=(mu_(2)-mu_(1))/(R)-((mu_(3)-mu_(2)))/(R) lt 0`
For diverging nature `v lt 0`
`(mu_(2)-mu_(1))/(R)lt (mu_(3)-mu_(2))/(R)`
`2mu_(2) lt mu_(1)+mu_(3)`