Physics
If the radius of curvature of a concave mirror is 20 cm, its focal length is:
- 10 cm
- 20 cm
- 40 cm
- 80 cm
Reflection of Light
20 Likes
Answer
10 cm
Reason — Focal length is half of radius of curvature, so it will be 10 cm.
Answered By
10 Likes
Related Questions
The seven colours in the spectrum of sunlight in order are represented as:
- VIBGYOR
- VIGYBOR
- BIVGYOR
- RYOBIVG
A ray of light passing through the centre of curvature of a spherical mirror, after reflection:
- passes through the focus
- passes through the pole
- becomes parallel to the principal axis
- retraces its own path
The image formed by a convex mirror is:
- erect and diminished
- erect and enlarged
- inverted and diminished
- inverted and enlarged
The image formed by a concave mirror is of the same size as the object, if the object is placed:
- at the focus
- between the pole and the focus
- between the focus and the centre of curvature
- at the centre of curvature