Question

When a magnetic needle is placed below a current carrying wire, current moves upward, there is a deflection towards east. but if the needle is placed above the conductor,(direction of current remains same), the deflection is towards west. Why?

Answer 1

This because, according to Right Hand Thumb rule, the magnetic field lines formed by the current carrying conductor are in the form of concentric circles in the direction of the fingers.
https://www.google.co.in/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&ved=0ahUKEwiE366b...
[It is the 4th figure on the page]
The figure provided in the above link explains it well. The magnetic needle aligns itself tangentially in the direction of the magnetic field. The magnetic field lines move to the right in front of the wire whereas it moves to the left behind the wire, so the compass needle aligns itself according to it.