CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2000

  • question_answer
    The value of\[[\overrightarrow{a}\text{ }\overrightarrow{a}+\overrightarrow{b}\text{ }\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c}]\]is:

    A)  \[{{[\overrightarrow{a}\text{ }\overrightarrow{b}\text{ }\overrightarrow{c}]}^{2}}\]                    

    B)  \[[\overrightarrow{a}\text{ }\overrightarrow{b}\text{ }\overrightarrow{c}]\]

    C)  \[2[\overrightarrow{a}\text{ }\overrightarrow{b}\text{ }\overrightarrow{c}]\] 

    D)  \[3[\overrightarrow{a}\text{ }\overrightarrow{b}\text{ }\overrightarrow{c}]\]

    E)  \[[\overrightarrow{a}\text{ }\overrightarrow{b}\text{ }\overrightarrow{c}]\]

    Correct Answer: B

    Solution :

    \[\therefore \] \[[\overrightarrow{a}\overrightarrow{a}+\overrightarrow{b}\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c}]\] \[=(\overrightarrow{a}\times (\overrightarrow{a}+\overrightarrow{b})).(\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c})\] \[=(\overrightarrow{a}\times \overrightarrow{b})(\overrightarrow{a}+\overrightarrow{b}+\overrightarrow{c})=(\overrightarrow{a}\times \overrightarrow{b}).\overrightarrow{c}=[\overrightarrow{a}\overrightarrow{b}\overrightarrow{c}]\]


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