Question

if the radius of curvature of concave mirror is 20 metre then what its focal length 20 m, or 10 m, or 50 m, or 5 m​

Answer 1

Answer:

10m

Explanation:

radius of curvature = 2 × focal length

focal length = $\frac{1}{2}$ × radius of curvature

                   = $\frac{1}{2}$ × 20

                   = 10m

Answer 2

Answer:- 10m

Explanation:-

Radius of curvature (R)= 20m

Focal length (f)= ???.

f= R/2

f= 20/2

f= 10m

So, Focal length (f)= 10m.....