Question

Ray diagram for two lenses kept at some distanœe given in the diagram, which of the following option is correct $\left(f_{1}, f_{2}=\right.$ focal length, $d=$ distance between lenses)

• A. $f_{1}+f_{2}>d$
• B. $f_{1}+f_{2} < d$
• C. $f_{1}+f_{2}=d$
• D. Combination behaves like converging lens

Answer 1

Answer: (C)

For parallel incidence image is at $f_{1}$ distance from $O _{1}$.
For final emergence to be parallel object for $II$ is at distance $f_{2}$ from $O_{2}$.
The distance between $I$ and $II$ would be $f_{1}+f_{2}$