Answer in Optics for Abhilash J.G. #87252
February 20th, 2023
We can write the mirror equation for a convex mirror as
“frac{1}{f} = frac{1}{d_o} – frac{1}{d_i} (1)”
where f is the focal length, d0 is the object distance, di the image distance
Using (1) we got:
“f=frac{( d_i times d_i)}{d_i- d_o} (2)”
where d0 = 25 cm
A convex mirror and plane mirror form two virtual images of the object. The two virtual image so formed coincide because the virtual images formed by the two mirrors don’t have any parallax.
The image distance is equal to: di=20 cm+20 cm – 25 cm = 15 cm
We find using (2): f = – 37.5 m
Answer:
A. 37.5cm