What can be a consequence of using a jack on uneven ground?

Using a jack on uneven ground can significantly increase the risk of the vehicle tipping. When a jack is positioned on an unstable surface, it may not provide the necessary support and balance required to keep the vehicle upright. This instability can cause the vehicle to sway or shift unexpectedly, leading to a potential accident where the vehicle could fall or tip over. Ensuring that the ground is level before using a jack is essential for maintaining safety during lifting operations.

The other options do not accurately reflect the reality of using a jack on uneven surfaces. Increased stability and safety cannot be achieved on an uneven surface, and there would indeed be effects on the lifting process rather than none at all. Improved efficiency would also not be possible under such conditions, as the jack's function relies on stability for effective operation.