What would happen to eddy currents if the frequency of the circuit is halved?

When the frequency of the circuit is halved, the rate at which the magnetic field changes in time is also reduced. Eddy currents are induced in conductive materials due to changes in magnetic fields, and their magnitude is proportional to the rate of change of the magnetic field with respect to time.

As the frequency decreases, the changes in the magnetic field occur more slowly, leading to lower induced electromotive forces (emf) and consequently weaker eddy currents. This results in a decrease in the overall strength of the eddy currents within the material.

Thus, halving the frequency decreases the frequency at which eddy currents can be induced, leading to a decrease in their magnitude. This is why the answer correctly indicates that eddy currents would decrease when the frequency is halved.