If we added half part of each convex and concave lens of a focal length f as shown the resolution of focal length will be

The focal length of a convex lens is

A compound lens has been formed by joinined a convex and a concave lens, each of focal length 30 cm. what is the focal length of the combination? What will be the power ?

We combined a convex lens of focal length f_(1) and concave lens of focal lengths f_(2) and their combined focal length was F . The combination of these lenses will behave like a concave lens, if

When a thin convex lens is put in contact with a thin concave lens of the same focal length (f), then the resultant combination has focal length equal to

A convex lens of focal length 0.5 m and concave lens of focal length 1 m are combined. The power of the resulting lens will be

The figure shows and equiconvex lens of focal length f. It the lens is cut along PQ, the focal length of each half will be