Question

Which statement is incorrect about unit vector?

Answer 1

Correct Question:

Which statement is incorrect about unit vector?

(1) Unit vector has unit but no dimension

(3) Unit vector is unitless and dimensionless

(2) Unit vector has both unit and dimension

(4) The magnitude of unit vector is zero

Solution:

• First of all, unit vector is a vector having magnitude of unity (i.e. 1 ) as well as a specific direction.

• Now, since vectors are physical quantities with dimensions, a unit vector is bound to have both units as well as dimensions.

• For example : $\hat{i}$ refers to a unit vector of magnitude 1 along the x axis. It will have dimensions of length (i.e L¹) and unit of metres/centi-meters, etc.

• Hence, Option 1) , 3) and 4) are incorrect.

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