KCET 2010 Physics Solved Paper

A point object O is kept at a distance of OP=u. The radius of curvature of the spherical surface APB is CP=R. The refractive index of the media are n1 and n2 which are as shown in the diagram. Then,
a) if n1>n2, image is virtual for all values of ' u '.
b) if n2=2n1, image is virtual when R>u.
c) the image is real for all values of u,n1 and n2. Here, the correct statement/s is/are .......................