An object is placed at 10 cm distance in front of concave mirror of radius of curvature 15 cm.

What is the nature and magnification of the image?

-3, real and inverted

u = -10cm , f = -7.5cm

$\frac{1}{v} = \frac{1}{f} - \frac{1}{u} = \frac{-1}{7.5} + \frac{1}{10} = \frac{-1}{30}$

$ \Rightarrow v = -30cm$

v is negative so image is real.

$m = -\frac{v}{u} = -3$

magnification is negative means its inverted.