Question

an object of h height is placed in front of a concave mirror of radius of curvature 40 cm find the position of imag when magnification is 2 and image is real​

Answer 1

Answer: 40 cm

Step-by-step explanation:

Radius of curvature, r= -40cm

Therefore, focal length,f= -20 cm

Magnification, m= -2

M= -v/u

-2= -v/u

-2u= v.....(1)

1/f = 1/v+ 1/u

-1/20= -1/2u + 1/u (frm (1))

-1/20 = 1/2u

-2u= 20

u= -10cm.........(2)

v= -2×-20

v=40cm