1. Tardigrade
  2. Question
  3. Physics
  4. Assertion: If dot product and cross product of vecP and vecQ are zero, it implies that one of the vector vecP and vecQ must be null vector. Reason: A null vector is a vector of zero magnitude.

Question Error Report

Thank you for reporting, we will resolve it shortly

Back to Question

Q. Assertion : If dot product and cross product of $\vec{P}$ and $\vec{Q}$ are zero, it implies that one of the vector $\vec{P}$ and $\vec{Q}$ must be null vector.
Reason : A null vector is a vector of zero magnitude.

AIIMSAIIMS 2018Motion in a Plane

Solution:

As per question, $\left|\vec{A} .\vec{B}\right|=\left|\vec{A}\times\vec{B}\right|=0$
This is possible if either A = 0 or B = 0.
Magnitude of a null vector is zero.