The part of circle x2 + y2 = 9 in between y = 0 and y = 2 is revolved about y-axis. The volume of generating solid will be
None of these
The angle between two diagonals of a cube will be
variable
None of these
B.
Let the cube be of side a.
O(0, 0, 0), D(a, a, a), B(0, a, 0), G(a, 0, a), then equation of OD and BG are respectively.
Hence, angle between OD and BG is
The lines and are coplanar and then equation to the plane in which they lie, is
x + y + z = 0
x - y + z = 0
x - 2y + z = 0
x + y - 2z = 0
Three forces of magnitudes 1, 2 and 3 dynes meet in a point and act along diagonals of three adjacent faces of a cube. The resultant force is
114 dynes
6 dynes
5 dynes
None of the above
The vectors AB = 3i + 5j + 4k and AC = 5i - 5j + 2k are side of a ABC. The length ofthe median through A is
5 units
10 units
Let a = 2i + j + k, b = i + 2j - 1, and a unit vector c be caplanar. If c is perpendicular to a, then c is