Question

Why is a convex mirror said to have a virtual principal focus?

Answer 1

Hint: The principal focus is defined as a point on the principal axis through which the rays which are parallel to the principal axis will pass. In a convex mirror, only virtual images are formed which means The rays from the object do not meet to make an image.

Complete answer:
The principal focus of a convex mirror is defined as the light beams that converge on the principal axis after reflecting from a convex mirror and are parallel to the principal axis. They either meet in person or appear to meet digitally. On the screen, the virtual image does not take shape.

If the hollow sphere's cut half is painted from the inside, the sphere's outside surface becomes the reflecting surface. A convex mirror is a name for this type of mirror. We know the rays which are parallel to the principal axis will pass through the focus of the mirror. From the above diagram, we can see that the rays are diverging if we extend the rays behind the mirror (virtually) we find the virtual principle focus of the convex mirror.Hence, a convex mirror is said to have a virtual principal focus

Note: A convex mirror is also known as a diverging mirror because when light strikes its reflecting surface, it diverges. Convex mirrors always produce virtual, erect, and reduced pictures, regardless of the distance between the item and the mirror.