The ornamental design for a cover used in electronic apparatus, as shown and described.
FIG. 1 is a perspective view of a cover used in electronic apparatus showing my design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a perspective view thereof, and the portion of the cord retainer in broken lines are shown for illustrative purposes only and form no part of the claimed design.