2. Solved Papers
  3. JEE Main & Advanced

JEE Main & Advanced JEE Main Paper (Held On 10-Jan-2019 Morning)

  • question_answer
    Let A be a point on the line \[\overrightarrow{\text{r}}=\,\,\left( 1-3\mu  \right)\widehat{i}+(\mu -1)\widehat{j}+\left( 2+5\mu  \right)\widehat{k}\] and \[B(3,\,\,2,\,\,6)\]be a point in the space. Then the value of \[\mu \] for which the vector AB is parallel to the plane \[x-4y+3z=1\] is- [JEE Main Online Paper (Held On 10-Jan-2019 Morning]

    A) \[\frac{1}{8}\]                          

    B) \[\frac{1}{2}\]

    C) \[\frac{1}{4}\]              

    D)                  \[-\frac{1}{4}\]

    Correct Answer: C

    Solution :

    \[\overrightarrow{AB}=(3-1+3\mu )\widehat{i}\,\,+(2-\mu +1)\widehat{j}+(6-2-5\mu )\widehat{k}\]\[=\,\,(2+3\mu )\widehat{i}+(3-\mu )\widehat{j}+(4-5\mu )\widehat{k}\] \[\overrightarrow{AB}\text{ }\bot \] normal of plane \[(2+3\mu )\left( 1 \right)+(3-u)\left( -4 \right)+(4-5\mu )\left( 3 \right)=0\] \[2-8\mu =0\,\,\Rightarrow \,\,\mu =\frac{1}{4}\]


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