Question

a concave mirror forms a real image 4times magnified at a distance of 60 CM from the mirror. calculate the focal length of the mirror. predict which case in this​

Answer 1

Answer:

For mirror u=

m

f(m−1)

In first case, u=

−4

f(−4−1)

In the second case, u+3=

−3

f(−3−1)

On solving, we get f=36cm

Answer 2

Answer:

Magnification=-4

v=-60

m=-(v/u)

-4=60/u

u=-15cm

1/v+1/u=1/f

-1/60+(-1/15)=1/f

-5/60=1/f

f=-12cm