Question

Assertion: When I P+ Q I = I P- QI, then P must be perpendicular to Q. Reason: The relation will hold even when Q is a null vector.

Answer 1

Answer:

The assertion is true and reason is false.

Explanation:

Assertion: I P+ Q I = I P- QI, then P must be perpendicular to Q.

Reason : The relation will hold even when Q is a null vector.

Now

$\left | P + Q \right |=\left | P - Q \right |\\\\P^2 + Q^2 + 2 P Q cos \theta =P^2 + Q^2 - 2 P Q cos \theta\\\\4 P Q cos \theta = 0 \\\\cos \theta = 0 \\\\\theta = 90 degree$

So, P and Q are perpendicular to each other.

So, the assertion is true.

Reason is false.