Question

If a = a1i + a2j and b = b1i +b2j, then direction of a x b is

(a) along x-axis

(b) along z-axis

(c) along a

(d) along y-axis​

Answer 1

The direction of $a\times b$ is perpendicular to the plane ($xy$-plane) where $a$ and $b$ sits on. Since $z$-axis is perpendicular to $xy$-plane, then the direction of $a\times b$ is along z-axis. Hence, the correct answer is (b).

Answer:

(b) along z-axis