Where in front of the concave mirror should an object be placed to get its virtual and erect image?

If the radius of curvature of a spherical mirror is $30 \ cm$,what is its focal length (in $cm$)?

If the image formed by a mirror for all positions of the object placed in front of it is always erect and diminished,what type of mirror is it? Draw a ray diagram to justify your answer. Where and why do we generally use this type of mirror?

$A$ ray of light $XY$ is incident on a mirror as shown in the figure. The angle of incidence for this ray is the angle between it and the line joining two other points in the figure. Name these two points and show the course of rays after reflection.

What is the distance between the principal focus and the center of curvature of a spherical mirror?

Why do we prefer a convex mirror as a rear-view mirror in vehicles?