Question

define cross product of two vectors when it is minimum.

Answer 1

we know that the cross product of two vectors A and B is given as

A X B = A.Bsinθ

now for A X B to be minimum sinθ should be minimum which occurs when θ = 180^o. The angle between A and B should be 180 degrees.

Physically this would mean that the cross product of two vectors would be minimum when they are anti-parallel to each other.