5. a current loop sits in the x ? y plane, centered on the origin. at the origin, the magnetic field due to the loop points in the positive z direction. what direction does the current in the loop run when viewed from the positive z direction?
(a) counter-clockwise.
(b) clockwise.
(c) the current is zero.
(d) more information is needed.

option (a)

Explanation:

The direction of current is given by the Maxwell's right hand thumb rule.

If we hold a current carrying conductor in our right hand such that the thumb indicates the direction of magnetic field then the curling of fingers give the direction of current.

Here the direction of current is in counter clockwise direction.

gans

explanation:

vestigial organs (like your appendix) are organs that no longer serve a purpose.

vapour or gas assuming atmospheriv pressure