What is the output of below algorithms on a disconnected Graph?
No.  The output of Dikstra's algorithm is a set of distances to each node.  It's not a graph or a tree.  This is true no matter whether the input graph is connected or disconnected.  The standard algorithm for Dijkstra's algorithm sets the distance correctly for all vertices in all components (not just the ones in the same connected component as the source).  The standard algorithm doesn't print anything, so if you are printing something, you're probably adding something extra to the standard algorithm, and we can't analyze that without seeing what your variation of the algorithm is.