question_answer

At what distance an object from a concave mirror having focal length of 20 cm should be placed so that the mirror forms a virtual image at 10 cm from the mirror?

A) \[-12\text{ }cm\]            

B) \[-6.6\text{ }cm\]

C) \[-30\text{ }cm\]                        

D) \[-25\text{ }cm\]

E) None of these