A concave mirror has a focal length of 20 cm. What is the radius of curvature of
Practice Questions
Q1
A concave mirror has a focal length of 20 cm. What is the radius of curvature of the mirror? (2021)
10 cm
20 cm
30 cm
40 cm
Questions & Step-by-Step Solutions
A concave mirror has a focal length of 20 cm. What is the radius of curvature of the mirror? (2021)
Step 1: Understand that a concave mirror has a focal length (f) which is given as 20 cm.
Step 2: Know the relationship between the radius of curvature (R) and the focal length (f). The formula is R = 2f.
Step 3: Substitute the given focal length into the formula. So, R = 2 * 20 cm.
Step 4: Calculate the result. R = 40 cm.
Focal Length and Radius of Curvature – The relationship between the focal length (f) and the radius of curvature (R) of a concave mirror, where R = 2f.
