CEE Kerala Engineering CEE Kerala Engineering Solved Paper-2006

  • question_answer
    The equation of the sphere whose centre is \[(6,-1,\text{ }2)\]and which touches the plane \[2x-y+2z-2=0,\]is:

    A)  \[{{x}^{2}}+{{y}^{2}}+{{z}^{2}}-12x+2y-4z-16=0\]

    B)  \[{{x}^{2}}+{{y}^{2}}+{{z}^{2}}-12x+2y-4z=0\]

    C)  \[{{x}^{2}}+{{y}^{2}}+{{z}^{2}}-12x+2y-4z+16=0\]

    D)  \[{{x}^{2}}+{{y}^{2}}+{{z}^{2}}-12x+2y-4z+6=0\]

    E)  \[{{x}^{2}}+{{y}^{2}}+{{z}^{2}}-12x+2y-4z-5=0\]

    Correct Answer: C

    Solution :

    Radius of sphere is J- distance of\[(6,-1,2)\] from \[2x-y+2z-2=0\] i.e.,        \[\left| \frac{12+1+4-2}{\sqrt{4+1+4}} \right|=\left| \frac{15}{3} \right|=5\] \[\therefore \]Equation of sphere is \[{{(x-6)}^{2}}+{{(y+1)}^{2}}+{{(z-2)}^{2}}=25\] \[\Rightarrow \] \[{{x}^{2}}+{{y}^{2}}+{{z}^{2}}-12x+2y-4z\] \[+36+1+4-25=0\] \[\Rightarrow \] \[{{x}^{2}}+{{y}^{2}}+{{z}^{2}}-12x+2y-4z+16=0\]


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