Question

(d) The value of the expression: \[ \hat{i} \cdot \hat{i} + \hat{j} \cdot \hat{j} + \hat{k} \cdot \hat{k} \]

• A. 0
• B. 1
• C. 2
• D. 3

Hint:

The dot product of a unit vector with itself is always 1, and with others, it's 0.

Answer 1

The Correct Option is D

The dot product of a unit vector with itself is equal to 1: \[ \hat{i} \cdot \hat{i} = 1, \quad \hat{j} \cdot \hat{j} = 1, \quad \hat{k} \cdot \hat{k} = 1. \] Adding these values: \[ 1 + 1 + 1 = 3. \]