Question

Assertion: if dot product and cross product of A and B are zero, it implies that one of the vector Aand B must be a null vector Reason: null vector i a vector with magnitude

Answer 1

ASSERTION:

If dot product and cross product of A and B are zero, it implies that one of the vector Aand B must be a null vector.

REASON:

Null vector is a vector with magnitude.

Assertion is true but reason is false.

$\vec{A} \: . \: \vec{B} = 0$

$\implies | \vec{A} | \times | \vec{B} | \times \cos( \theta) = 0$

• This means that either A and B are perpendicular or Either A or B is a null vector.

Again, cross product is also zero:

$\vec{A} \: \times \: \vec{B} = 0$

$\implies | \vec{A} | \times | \vec{B} | \times \sin( \theta) = 0$

• This means that either A and B are parallel or Either A or B is a null vector.

Hope It Helps.