A) 2
B) 3
C) 4
D) 1
Correct Answer: B
Solution :
[b] Center of the sphere is \[\left( -1,\text{ }1,\text{ }2 \right)\] and its radius\[=\sqrt{1+1+4+19}=5\] CL, perpendicular distance of C from plane, is \[\left| \frac{-1+2+4+7}{\sqrt{1+4+4}} \right|=4\] Now \[A{{L}^{2}}=C{{A}^{2}}-C{{L}^{2}}=25-16=9\] Hence, radius of the circle\[=\sqrt{9}=3\]You need to login to perform this action.
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