Let `veca,vecb,vecc` be three unit vectors such that `3veca+4vecb+5vecc=vec0`. Then which of the following statements is true? (A) `veca` is parrallel to vecb` (B) `veca` is perpendicular to vecb` (C) `veca` is neither parralel nor perpendicular to `vecb` (D) `veca,vecb,vecc` are copalanar

Options

A. `veca` is parallel to `vecb`
B. `veca` is perpendicular to `vecb`
C. `veca` is neither parallel nor perpendicular to `vecb`
D. none of these

Answer

D

Explanation

`3veca + 4vecb + 5vecc =0`
Hence `veca, vecb and vecc` are collinear.
No other conclusion can be derived from it.