• # question_answer The focal length of a concave mirror is $50cm.$ Where an object be placed so that its image is two times and inverted A)            75 cm                                       B)            72 cm C)            63 cm                                       D)            50 cm

For real image m = ? 2,     so by using $m=\frac{f}{f-u}$            $\Rightarrow -\ 2=\frac{-\,50}{-50-u}\Rightarrow u=-\ 75\ cm$