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Since, the speed of light along y-direction is more than the x and z-direction, the waves generated from the wavefront at the origin (source) will travel more distance (for a fixed time interval) along y-direction than along x- and z-direction. As such, the wavefront at any later instant of time will be an ellipsoid and stretched out along the y-axis.
Regards
Since, the speed of light along y-direction is more than the x and z-direction, the waves generated from the wavefront at the origin (source) will travel more distance (for a fixed time interval) along y-direction than along x- and z-direction. As such, the wavefront at any later instant of time will be an ellipsoid and stretched out along the y-axis.
Regards