question_answer

The magnitude of vector \[\overrightarrow{A},\,\overrightarrow{B}\] and \[\overrightarrow{C}\] are respectively 12, 5 and 13 units and \[\overrightarrow{A}+\overrightarrow{B}=\overrightarrow{C}\] then the angle between \[\overrightarrow{A}\] and \[\overrightarrow{B}\] is                                      [CPMT 1997]

A)                 0             

B)                 \[\pi \]

C)                 \[\pi /2\]             

D)                 \[\pi /4\]

Correct Answer: C

Solution :

                    \[C=\sqrt{{{A}^{2}}+{{B}^{2}}}\]                 The angle between A and B is \[\frac{\pi }{2}\]