Work done by 2 Magnets when they attract each other

Question

]1 Assuming that whatever is written (in the picture) is true,then how is work done when 2 magnets attract each other in space. Even they should not do any work but by observation, they do come close

Answer 1

Lenz's law applies to induction in coils or any similar geometry where a changing magnetic field induces a current in a conductor. The book is pointing out that if the induced current reinforced the magnetic field causing the current then you'd get a runaway.

If you have two permanent magnets, e.g. ferromagnets, the problem disappears because the magnetic field is due to the magnetic dipole of electrons so it is not due to an induced current and doesn't depend on the motion of the magnets.

If you have two electromagnets then the field is due to the current flowing in the electromagnets due to an external power supply, so again it is not due to an induced current. For two electromagnets there will be a small induced field opposing their motion as they are brought together, but it will be negligible compared to the current from the external power supply. So again the field does not depend on the motion of the magnets.