# Moving charges and magnetism

Suyash Singh

## Homework Statement

current in wire is in east to west direction.direction of magneetic field below the line

## Homework Equations

right hand thumb rule

## The Attempt at a Solution

i used the right hand thumb rule to find the direction of magnetic field but the magnetic field comes out in in the upwards direction(out of plane) but the answer is in the south direction

Thankyou

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ehild
Homework Helper

## Homework Statement

current in wire is in east to west direction.direction of magneetic field below the line

## Homework Equations

right hand thumb rule

## The Attempt at a Solution

i used the right hand thumb rule to find the direction of magnetic field but the magnetic field comes out in in the upwards direction(out of plane) but the answer is in the south direction

Thankyou
East to West defines a line, what plane do you speak about?

cnh1995
Homework Helper
Gold Member
in in the upwards direction(out of plane)
Plane of the paper?

ehild
Homework Helper
Plane of the paper?
The paper can be horizontal, vertical, or can stand in any direction.

East, West, North, South are defined in a horizontal plane.
The magnetic field lines are circles around the wire, with the wire as axis. Take a pencil as wire and do the right thumb rule in reality. In what direction do your fingers point under the wire?
This is a very bad drawing, I was not able to make a better one. The wire and the cardinal directions are in the horizontal plane.

Suyash Singh
East to West defines a line, what plane do you speak about?
the plane of paper since north south east west are in plane of paper.

Suyash Singh

this is the answer but my fingers are coming out of the plane of paper
like this

and this the actual question

I could get the numerical answer but not the the direction

ehild
Homework Helper
View attachment 206877
this is the answer but my fingers are coming out of the plane of paper
like this
View attachment 206878
and this the actual question
View attachment 206879
I could get the numerical answer but not the the direction
Your fingers come out of the paper beside the wire or above it. Just under the wire the fingers stand in the North-West direction, and having short fingers, the tips would point to the South. The green vector represents the direction of the magnetic field under the wire.

This is a side view: