The direction of the vector product A cross B is given by
- A. the direction of A
- B. the direction of B
- C. the bisector of the angle between A and B
- D. the right hand rule, perpendicular to the plane containing A and B
Explanation
Curling the fingers of the right hand from A to B points the thumb along A cross B, which is perpendicular to both vectors. Because the sense reverses when the order is swapped, B cross A equals minus A cross B, so the cross product is not commutative. Torque and magnetic force are both defined this way.