Home › CBSE Class 10 › Physics › Light - Reflection and Refraction › The principal focus of a concave mirror is the p…
The principal focus of a concave mirror is the point where:
AAll light rays meet after reflection
BParallel rays converge after reflection
CParallel rays diverge after reflection
DThe centre of curvature is located
Answer & Solution
Correct answer: B. Parallel rays converge after reflection
1. A concave mirror's focus is where rays parallel to the principal axis CONVERGE after reflection.
2. Only paraxial rays (close to the axis) converge sharply.
3. A convex mirror has a VIRTUAL focus — rays only appear to diverge from it.
_Source: NCERT Class 10 Science Ch 9 §9.2.1 Principal Focus_
Related questions
A convex lens of focal length 20 cm has an object placed at 30 cm from it. The image distaAn object placed at the focus of a concave mirror produces an image:Total internal reflection occurs when light travels from:The lens formula for a thin lens is:A convex lens of focal length 25 cm has power equal to:Power of a lens of focal length f (in metres) is given by:Snell's law of refraction is:The refractive index of a transparent medium is defined as: