NDA 2021 Maths · Mathematics · Vector Algebra · medium

For any vectors vec a and vec b, vec a×vec b is parallel to vec a. 2. The scalar product vec a·vec b is a vector.

Single correct option

Which of the statements is/are correct? 1. For any vectors

\vec a

and

\vec b

\vec a\times\vec b

is parallel to

\vec a

. 2. The scalar product

\vec a\cdot\vec b

is a vector.

Show answer and solution

Answer: (D) Neither 1 nor 2

The cross product is perpendicular to both

\vec a

and

\vec b

, never parallel to them (unless it is zero), so statement 1 is false. The scalar product is a scalar, so statement 2 is false. Neither is correct.

Original question written in the NDA 2021 Maths pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake