Question

Why is groove provide in a saucer

Answer 1

Groove is provided in a saucer so that appropriate support is provided to the cup.

Grip is provided so that the cup might not fall while placing on it.

If grove is not provided, then due to change in the inertia of direction it can readily fall down.

Answer 2

circular groove is provided in the saucer so that in case of sudden shake the couple not toppled or fall from the saucer.