Question

An object is placed 10cm in front of a concave mirror.A real image magnefied two times is formed. calculate

Answer 1

Answer:

u = -10

m = -2 (as the image is real and inverted)

m = -v/u

-2 = -v/-10

-2 = v/10

v = -20.

The image is formed 20cm in front of the mirror (as indicated by the negative sign)

Using the mirror formula

1/v + 1/u = 1/f

1/-20 + 1/-10 = 1/f

(-1 - 2)/20 = 1/f (taking LCM)

f = -20/3

f = -6.66 cm