The focal length of a mirror is +20 cm. Is it concave or convex?

An object is plced at a distance of 25 cm from a shperical mierror and its image is formed behind the mirror at a distance of 5 cm.Find the focal length of the mirror.Is the mirror concave or convex in nature?

Define the focal length of mirror

The size of the image of an object,which is at infinity, as formed by a convex lens of focal length 30 cm is 2 cm. If a concave lens of focal length 20 cm is placed between the convex lens and the image at a distance of 26 cm from the convex lens, calculate the new size of the image

A convex mirror forms an imge,which is 1//n times the size of the object .If the focal length of the mirror is f,the distance of the object is

Find the focal lengh of a convex miror and concave mirror each having radius of curvature of 20 cm.

Which spherical mirror is called a divergent mirror-concave or convex?

What happens to focal length of a concave mirror when immersed in water ?

What is the focal length of a combination of two concave lenses both of focal length 20 cm ?Is the system,a converging or a diverging lens?Ignore thickness of the lenses.

An object is at a distance of 10 cm from a spherical mirror and the image of the object is at a distance of 30 cm from the mirror on the same side as the object.Is the mirror concave or convex?What is its focal length?