A convex lens has a positive focal length because it converges light rays to a point.

A concave lens has a negative focal length because it diverges light rays from a point.

This equation is known as the thin lens equation and is used to calculate the image distance and object distance for a lens.

Magnification is the ratio of the image height to the object height and is given by M = v/u.

All of the given statements are true. A real image can be projected onto a screen, while a virtual image cannot. A real image is formed by converging light rays, while a virtual image is formed by diverging light rays. A real image is always upright, while a virtual image can be upright or inverted.

The focal point of a mirror is the point where light rays converge after reflection.

A concave mirror has a negative focal length because it converges light rays to a point.

A convex mirror has a positive focal length because it diverges light rays from a point.

This equation is known as the mirror equation and is used to calculate the image distance and object distance for a mirror.

Magnification is the ratio of the image height to the object height and is given by M = v/u.

All of the given statements are true. A real image can be projected onto a screen, while a virtual image cannot. A real image is formed by converging light rays, while a virtual image is formed by diverging light rays. A real image is always upright, while a virtual image can be upright or inverted.

Convex lenses are primarily used to correct nearsightedness (myopia) by converging light rays onto the retina.

Concave lenses are primarily used to correct farsightedness (hyperopia) by diverging light rays away from the retina.

Concave mirrors are used for a variety of purposes, including focusing light, magnifying objects, and creating virtual images.

Convex mirrors are primarily used to see around corners or to provide a wider field of view, as in the side mirrors of vehicles.