1)

The radius of the sphere  x2+y2+z2=49,2x+3yz514=0 is


A) 6

B) 26

C) 46

D) 66

Answer:

Option B

Explanation:

The sphere, x2+y2+z2=49 has centre at the origin (0, 0, 0) and radius 7.

1052021955_VITEE M.JPG

 DisTance of the plane 2x+3yz514=0

from the origin

|2(0)+3(0)(0)514|22+32+(1)2

= |514|14 = 51414 = 5

Thus in Figure ; OP = 7, ON = 5

NP= OP2 - ON2 = 72 - 52 = 49 - 25 = 24

.'. NP = 26 Hence the radius of the circle = NP = 26