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
15 Likes
Answer
10 cm
Reason — Focal length is half of radius of curvature, so it will be 10 cm.
Answered By
8 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