The net of a cube is the one which has the faces arranged in such a way that it makes a complete cubic structure
(i) In the given figure, the net cannot be folded into a cube by folding the six faces of the net. Therefore, it is not a cube net.
(ii) In the given figure, the net can be folded into a cube when its faces are folded one over the other. Therefore, it is a cube net.
(iii) In the given figure, the net can be folded into a cube when its faces are folded one over the other. Therefore, it is a cube net.
(iv) In the given figure, the net cannot be folded into a cube by folding the six faces of the net. Therefore, it is not a cube net.
(v) In the given figure, the net can be folded into a cube when its faces are folded one over the other. Therefore, it is a cube net.