question_answer

An object is placed at 10 cm from the lens. If the final image is formed at the optical centre of lens, then focal length of mirror will be

A)  +10 cm                

B)  - 8 cm

C)  + 8 cm                 

D)  - 10 cm

Correct Answer: B

Solution :

 Idea This question is based on the combination of mirror and lens. By drawing ray diagram one can easily solve this question. From the ray diagram, it is easy to understand the situations. TEST Edge Different   questions   where   the combination of two lenses or two mirrors could be asked from this topic.