M = \(\frac{Height\, of\, image}{Height\, of\, object}\)
= \(\frac{h_1}{h_0}\) = \(\frac{-u}{v}\)
Let the height of object be h then height of image h = – 3h
= \(\frac{3h}{h}\) = \(\frac{-v}{u}\) = \(\frac{v}{u}\) = 3
∴ Distance of object, u = – 10 cm
v = 3 × (10) = – 30 cm
Here – sign indicates, image is real and it is 30 cm in front of concave mirror.