In a concave mirror, an object is placed at a distance `d_1` from the focus and the real image is formed aat a distance `d_2` from the focus. Then the focal length of the mirror is :

In a concave mirrorr experiment, an object is placed at a distance x_(1) from the focus and the image is formed at a distance x_(2) from the focus. The focus length of the mirrorr would be

An object is placed at a distance of 30 cm from a concave mirror and its real image is formed at a distance of 30 cm from the mirror. The focal length of the mirror is

With a concave mirror, an object is placed at a distance x_(1) from the principal focus, on the principal axis. The image is formed at a distance x_(2) from the principal focus. The focal length of the mirror is

With a concave mirror, an object is placed at a distance x_(1) from the princiipal focus, on the principal axis. The image is formed at a distance x_(2) from the principal focus. The focal length of the mirror is

With a concave mirror, an object is placed at a distance 9cm from the principal focus, on the principal axis. The image is formed at a distance 16cm from the principal focus. The focal length of the mirror is

An object is placed at a distance x_1 from the principal focus of a lens and its real image is formed at a distance x_2 from the another principal focus. The focal length of the lens is

An object is placed in front of a concave mirror at a distance of 7.5 cm from it. If the real image is formed at a distance of 30 cm from the mirror, find the focal length of the mirror. What would be the focal length if the image is virtual.

An object is placed at a distance of 25 cm from a spherical mirror, its image is formed behing the mirror at a distance of 5 cm. The focal length and type mirror is