BCECE Engineering BCECE Engineering Solved Paper-2014

  • question_answer
    The    angle    between    the    line \[\frac{3x-1}{3}=\frac{y+3}{-1}=\frac{5-2z}{4}\]and   the   plane\[3x-3y-6z=10\] is equal to

    A) \[\frac{\pi }{6}\]                                              

    B) \[\frac{\pi }{4}\]

    C) \[\frac{\pi }{3}\]                                              

    D) None of these

    Correct Answer: D

    Solution :

     Given line can be rewritten as\[\frac{x-\frac{1}{3}}{1}=\frac{y+3}{-1}=\frac{\left( z-\frac{5}{2} \right)}{-2}\]and equation of plane is rewritten as \[x-y-2z=\frac{10}{3}\] Here, direction ratios of line and plane are\[{{a}_{1}}=1,{{b}_{1}}=-1\] and \[{{c}_{1}}=-2\]and   \[{{a}_{2}}=1,{{b}_{2}}=-1\]and \[{{c}_{2}}=-2\]x Now, \[\sin \theta =\frac{{{a}_{1}}{{a}_{2}}+{{b}_{1}}{{b}_{2}}+{{c}_{1}}{{c}_{2}}}{\sqrt{a_{1}^{2}+b_{1}^{2}+c_{1}^{2}\sqrt{a_{2}^{2}+b_{2}^{2}+c_{2}^{2}}}}\] \[=\frac{1\times 1+(-1)\times (-1)+(-2)\times (-2)}{\sqrt{1+1+4}\sqrt{1+1+4}}\] \[=\frac{1+1+4}{\sqrt{6}\sqrt{6}}=\frac{6}{6}=1\]             \[\Rightarrow \]               \[\theta =\frac{\pi }{2}\]


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