A horizontal conductor is oriented north south and carries some current. A positively charged particle located vertically above it and having a velocity directed north ward experiences an upward force. What is the direction of the force if this charged particle were located to the east of the conductor and had a velocity directed towards the conductor.

Lets assume current is in south direction.

Case 1: 

Direction of magnetic field is towards west.

Direction of velocity is towards north.

$\overrightarrow{F}=q\left(\overrightarrow{v}\times \overrightarrow{B}\right)$

So, Direction of force is towards vertically up.

Thus, our assumption is correct.

Case 2:

Direction of magnetic field is towards vertically up.

Direction of velocity is towards west.

$\overrightarrow{F}=q\left(\overrightarrow{v}\times \overrightarrow{B}\right)$

So, Direction of force is towards north.