Two convex lenses of focal lengths `f_(1)` and `f_(2)` form imgaes with magnification `m_(1)` and `m_(2)` when used individually for an object kept at the same distance from the lenses. Them `f_(1)//f_(2)` is

Options

A. `(m_1(1+m_1))/(m_2(1+m_2))`
B. `(m_1(1+m_2))/(m_2(1+m_1))`
C. `(m_2(1+m_2))/(m_1(1+m_2))`
D. `(m_2(1+m_2))/(m_1(1+m_1))`

Explanation

Note : Focal length for convex lens is always positive
`m=(f)/(f+mu)`
`mu=((1-m_1)/(m_1))f_1`
`mu_2=((1-m_2)/(m_2))f_2`
`mu_1=mu_2`
`(((m-1))/(m_1))f_1 .((m_2-1))/(m_2)xxf_2`
`(f_1)/(f_2)=(m_1)/(m_2)((m_2-1)/(m_1-1))` .