Question

Which of the following statement(s) is/are correct?

• A. Displacing a vector parallel to itself leaves the vector unchanged.
• B. Three equal vectors cannot add upto zero.
• C. If $| A + B | \neq| A - B |$ they are perpendicular vectors.
• D. Both (b) and (c)

Answer 1

Answer: (A)

Three equal vectors can add upto zero when each of them is inclined at $120^{\circ}$ with the other.
If $| A + B |=| A - B |$, they are inclined at $90^{\circ}$ as shown below.

In this figure, length of $M N$ is equal to length of $M O$.
So, $| A + B |=| A - B |$.
Thus, the statement given in option (a) is correct, rest are incorrect.