question_answer

An object is placed 12 cm to the left of a converging lens of focal length 8 cm. Another converging lens of 6 cm focal length is placed at a distance of 30 cm to the right of the first lens.  The second lens will produce             [KCET 2002]

A)            No image                               

B)            A virtual enlarged image

C)            A real enlarged image      

D)            A real smaller image

Correct Answer: C

Solution :

                   For lens (1) \[\frac{1}{f}=\frac{1}{v}-\frac{1}{u}\Rightarrow \frac{1}{(+8)}=\frac{1}{v}-\frac{1}{(-12)}\]                    \[\Rightarrow v=24\]\[cm\] i.e. Image \[A'B'\] is obtained 6 cm before the lens 2 or at the focus of lens 2. Hence final image formed by lens 2 will be real enlarged and it is obtained at \[\infty \].