Can a vector have zero component along line and still have non zero magnitude?

Can a body have zero velocity and still be accelerating ?

The two ends of a spring are displaced along the length of the spring. All displacements have equal magnitudes. In which case or cases the tension or compression in the spring will have as maximum magnitude?

Vector is having

If the external torque acting on the body zero, the component of ________ along the axis of rotation is constant.

Write two different vectors having same magnitude.