Two identical circular coils and are kept on a horizontal tube side by side without touching each other. If the current in the coil increases with time, in response, the coil is repelled. It is so because when the current in coil is changed, the magnetic field associated with it also changes. As a result, the magnetic field around coil B also changes. This change in magnetic field lines around coil B induces an electric current in it. Now as the same current is flowing in both the coils and in same direction, hence they both will repel each other.