Yes. In case of a DC motor, if you place a circular coil instead of rectangular one, it
will still rotate. Consider the recangular coil first, the force on the coil is the result
of cross product of current direction and magnetic field direction that comes
perpendicular to both flow of current and magnetic field due to magnets and hence
In case of a circular coil, the current is along the same plane as that of the recatngular
coil case, magnetic field due to the magnets is still in the same direction. Hence in this
case also the cross prodcut will be non zero and will result in the net force and consequently
the motor will start revolving.