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General Knowledge · Q522

Practice

Competitive Exams · General Knowledge · question 522

Q522

The focal length of a concave mirror with a radius of curvature of 20.0 cm is :

A.
20 cm
B.
5 cm
C.
10 cm
Answer
D.
15 cm

Answer: Option C

Solution

Answer: Option C
Solution:
Let us assume f is focal length
R is radius of curvature
According to the formula R = 2f
f = R/2
= 20/2
= 10 cm