Explain an experiment to determine the focal length of a concave mirror by u-v method.

In the experiment to determine the focal length of a concave mirror by graphical methods the u - v graph is

Four students A, B, C and D performed the experiment to determine the focal length of a concave mirror by obtaining the image of a distant tree on a screen. They measured the distances between the screen and the mirror as shown in the diagrams given below : The correct value for focal length will be obtained by the student :

In order to determine the focal length of a concave mirror by obtaining the image of distant object on screen, the position of screen should be

In an optical bench experiment to measure the focal length of a concave mirror random error in focal length will be

A double convex lens (R_(1) = R_(2) = 10 cm) (mu = 1.5) having focal length equal to the focal length of a concave mirror. The radius of curvature of the concave mirror is

A double convex lens ( R_(1)=R_(2)=10 cm ) having focal length equal to the focal length of a concave mirror. The radius of curvature of the concave mirror