Question

Identify the unit vector in the following.

Answer 1

A vector is said to be unit vector when magnitude of it is unity.
I mean, if A is an unit vector then, |A| = 1

Let's check which is unit vector ,
option (a) :- i + j
Magnitude = √(1² + 1²) = √2 ≠ 1
∴ i + j is not a unit vector

Option (b) :- i/√2
magnitude = 1/√2 ≠ 1
not an unit vector

option (c) :- k - j/√2
magnitude = √(1² + 1/√2²) = √3/√2 ≠ 1
not an unit vector

option (d) :- (i + j)/√2
magnitude = √(1/2 + 1/2) = 1
It is an unit vector

Hence, option (d) is correct