Why the whole wire moves when lorentz force acts? We know that magnitute of lorentz force is directly proportional to the current in the current carrying wire.
But since the force is acting on the charges,shouldn't they get exited or thrown out when the magnitude of the force crosses the binding force between them and opposite charges?Please tell me if such phenomenon occurs.
Also when electrons move in a wire we usually say positve charges are moving in opposite directions,though not actually,I am talking about holes moving.So should the lorentz force also act on the positive charges?
 A: Each charge carrier in the wire generates its own magnetic field and, as you pointed out, the overall magnetic field generated by the wire is somehow proportional to the current flow within the wire. And yes, the charge carriers do feel their own magnetic field, but usually this is a negligible effect and almost never enough for the particles to "break" the wire and exit out.

,shouldn't they get exited or thrown out when the magnitude of the force crosses the binding force between them and opposite charges?

If the magnitude of the applied force due to their own magnetic field were so strong to break the normal reaction of the wire upon the particles themselves then yes, this might happen. But for standard particles and standard wires this is just never the case. Wires are usually built taking into account all the possible counter-terms generated by the self-interactions. Notice that in general everything that is allowed by nature to occur does in fact occur, but the overall contributions and effects that you see are only the ones of the prominent forces.
Furthermore

Also when electrons move in a wire we usually say positve charges are moving in opposite directions,though not actually,I am talking about holes moving.So should the lorentz force also act on the positive charges?

the Lorentz force acts on every charge, whether positive or negative. Then particles move according to the Newton's law, taking into account all possible minus signs. Holes are not actual particles: what happens is that the electrons move away and leave their original positions, which can be replaced by other electrons and so on and so forth. The overall effect is as if there were positive charges moving towards the opposite direction, but that is just a pictorial representation to take into account the displacement of the single electrons from the original position.
