A straight transmission cable carries a steady direct current I I\,I from West to East, as shown in the diagram. A uniform external magnetic field B⃗\vec{B}B is directed horizontally from East to West.
What is the direction of the magnetic force acting on this section of the cable?
Vertically upwards (towards the sky)
Vertically downwards (towards the ground)
Horizontally towards the North
There is no magnetic force acting on the cable