FIG. 1 is a perspective view of an electric cooktop showing our ornamental design;
FIG. 2 is a front side view of the electric cooktop shown in FIG. 1;
FIG. 3 is a top plan view of the electric cooktop shown in FIG. 1; and
FIG. 4 is a right side view of the electric cooktop shown in FIG. 1; and,
FIG. 5 is a left side view of the electric cooktop shown in FIG. 1.
The broken line showing of environment in the drawings is for illustrative purposes only and forms no part of the claimed design.