An adapter having a housing, a ground clip and an adapter subassembly all located in the housing. Alternatively, the electric power steering apparatus calculates a base electric angle at which the q-axis current is equal to or smaller than a third threshold value though the q-axis voltage is being applied, and determines an abnormal phase based on the base electric angle. The apparatus may further include a single heating element configured to heat both the first segment and the second segment, wherein a light propagation direction at a point in the second segment differs by at least 90 degrees with respect to a light propagation direction at the point in the first segment.