Question

A current moving upward along a vertical wire generates a magnetic field in which direction?

a) pointed upward

b) pointed downwards

c) counter-clockwise around the wire

d) clockwise around the wire

Answer 1

C) Counter-clockwise around the wire.

The direction of current is given by right hand rule. According to this we take the right hand tumb in the direction of current in the wire. Then all other fingers are curved such that the direction pointed by curved finger gives direction of magnetic field.

In the above stated question it is given that the direction of current is upwards hence right hand thump points upwards and the fingers will be curved in a counter-clockwise direction. Hence magnetic field moves in a counter clockwise direction around the wire.