Haryana PMT Haryana PMT Solved Paper-2005

  • question_answer
    Which of the following is in correct?

    A)  \[\overrightarrow{\text{a}}\text{.(}\overrightarrow{\text{b}}\text{+}\overrightarrow{\text{c}}\text{)=}\overrightarrow{\text{b}}\text{.}\,\overrightarrow{\text{a}}\text{+}\overrightarrow{\text{a}}\text{.}\,\overrightarrow{\text{c}}\]

    B) \[\overrightarrow{\text{a}}\text{ }\!\!\times\!\!\text{ (}\overrightarrow{\text{b}}\text{+}\overrightarrow{\text{c}}\text{)=}\,\text{(}\overrightarrow{\text{a}}\text{ }\!\!\times\!\!\text{ }\overrightarrow{\text{c}}\text{) }\!\!\times\!\!\text{ }\,\text{(}\overrightarrow{\text{a}}\text{ }\!\!\times\!\!\text{ }\overrightarrow{\text{b}}\text{)}\]

    C) \[\overrightarrow{\text{a}}\text{ }\!\!\times\!\!\text{ (}\overrightarrow{\text{b}}\text{.}\overrightarrow{\text{c}}\text{)=}\,\text{(}\overrightarrow{\text{a}}\text{ }\!\!\times\!\!\text{ }\overrightarrow{\text{b}}\text{)}\text{.}\,\text{(}\overrightarrow{\text{a}}\text{ }\!\!\times\!\!\text{ }\overrightarrow{\text{c}}\text{)}\]

    D) \[\text{(}\overrightarrow{\text{b}}\text{.}\overrightarrow{\text{c}}\text{)}\,\overrightarrow{\text{a}}\text{=}\overrightarrow{\text{a}}\,\text{(}\overrightarrow{\text{a}}\text{.}\overrightarrow{\text{b}}\text{)}\]

    Correct Answer: A

    Solution :

                    \[\overrightarrow{a}\]is a vector but \[(\overrightarrow{b}.\overrightarrow{c})\] is scalar quantity and the cross product between a vector and a scalar is undefined.


You need to login to perform this action.
You will be redirected in 3 sec spinner