A point object O is kept at origin. When a concave mirror M1 placed at x = 6 cm, image is formed at infinity. When M1 is replaced by another concave mirror M2 at same position, image is formed at x = 30 cm, then ratio of the focal length of M1 to that of M2 is (A) 3/4 (B) 4/3 (C) 5 (D) 1/5
Answers
Answered by
5
When M1 is placed, the object is placed at 6cm the image formed is at infinity
Therefore, Focal length of M1 = F1 = -6cm
In the second case,
u = -6cm
v = -30cm
Using mirror formula,
1/f = 1/v + 1/u
f = uv/(u+v) = 180/(-36) = -5cm
F2 = -5cm
Therefore,
Ratios of focal length = -6:-5 = 6:5
Hope this is helpful to you
Pls mark as brainliest
Follow me and I'll follow you back
Answered by
1
Answer:
c
Explanation:
Similar questions