If any component of a vector is not zero, then the vector is not zero.
No, for a vector to be zero, all of its components must be zero. If only one component is not zero, then the vector itself cannot be zero.
No, a vector cannot have zero magnitude if one of its components is not zero. The magnitude of a vector is determined by the combination of all its components, so if any component is not zero, the vector will have a non-zero magnitude.
Yes, the component of a non-zero vector can be zero. A non-zero vector can have one or more components equal to zero while still having a non-zero magnitude overall. For example, in a two-dimensional space, the vector (0, 5) has a zero component in the x-direction but is still a non-zero vector since its y-component is non-zero.
When the direction of the vector is vertical. Gravitational force has zero horizontal component.
No. The magnitude of a vector can't be less than any component.
No never
No.
No.
Yes. A vector in two dimensions is broken into two components, a vector in three dimensions broken into three components, etc... If the value of all but one component of a vector equal zero then the magnitude of the vector is equal to the non-zero component.
No. The answer does assume that "components" are defined in the usual sense - that is, a decomposition of the vector along a set of orthogonal axes.
Their directions are perpendicular.
Yes, if it has a non-zero component along some other line - usually, but not necessarily orthogonal.