Chapter 34, Problem 113E

(a)

To determine

The radius of the ray bundle decreases to ${r^{\prime }}_0=r_0\left(f_1-d\right)/f_1$ at the point that it enters the diverging lens.

(b)

To determine

The final image $I\text{'}$ is formed a distance ${s^{\prime }}_2=\left(\left|f_2\right|\left(f_1-d\right)\right)/\left(\left|f_2\right|-f_1+d\right)$ to the right of the diverging lens.

(c)

To determine

The effective focal length is given by $f=f_1\left|f_2\right|/\left(\left|f_2\right|-f_1+d\right)$.

(d)

To determine

The maximum and minimum focal lengths of the combination if $f_1=12.0\text{cm}$, $f_2=-18.0\text{cm}$ and the separation $d$ is adjustable between $0$ and $4.0\text{cm}$. And the value of $d$ gives if $f=30.0\text{cm}$.