Question

Unit vector which is perpendicular to the vector 4î + 3ĵ is _____

(a) ĵ

(b) î

(c) 4î + 3ĵ

(d) \(\hat{z}\)

This question was addressed to me in an online quiz.

This interesting question is from Vector Addition topic in chapter Motion in a Plane of Physics – Class 11

Answer 1

The correct option is (d) \(\hat{z}\)

Explanation: The dot product of any two vectors which are perpendicular to each other is 0. The dot product of all the vectors in the options with 4î + 3ĵ is non-zero except for \(\hat{z}\). Hence \(\hat{z}\) is perpendicular to the given vector.