# Conventional current, magnetic fields and magnetic poles of different diagrams

## Homework Statement:

Draw the direction of the conventional current or the magnetic field lines. Also indicate the location of the north and south poles where appropriate.

## Homework Equations:

#1, 2, 3 Right hand rules

I need to do question 1. I understand the right hand rules but am lost on what to do here.

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berkeman
Mentor
You need to show more effort before we can offer tutorial help.

Can you use the Right-Hand Rule to draw the B-field lines for part (b)?

You need to show more effort before we can offer tutorial help.

Can you use the Right-Hand Rule to draw the B-field lines for part (b)?
Well the dot is where in comes in and the X is where it comes out, so would it be lines coming out of the dot around towards the X?

berkeman
Mentor
No. Can you show an illustration of the Right-Hand Rule for determining the direction of B-field lines circulating around a current-carrying wire?

berkeman
Mentor
It's a cloud!

Is there a figure in your textbook? If so, you can take a good quality picture with your phone using flash, and attach the JPEG file. Or, you can use Google Images to find good images of what I was asking about.

It's a cloud!

Is there a figure in your textbook? If so, you can take a good quality picture with your phone using flash, and attach the JPEG file. Or, you can use Google Images to find good images of what I was asking about.

berkeman
Mentor
Yes, so now you can draw the B-fields circulating the two wires in figure (b). Draw the B-field due to each wire, and then look to see how they add/subtract/cancel in various regions around the wires...

Note -- you have shown figures for when the current-carrying wire is vertical, so you will need to mentally rotate that into the horizontal plane, facing you and facing away from you...

Yes, so now you can draw the B-fields circulating the two wires in figure (b). Draw the B-field due to each wire, and then look to see how they add/subtract/cancel in various regions around the wires...

Note -- you have shown figures for when the current-carrying wire is vertical, so you will need to mentally rotate that into the horizontal plane, facing you and facing away from you...
Like this?

berkeman
Mentor
Don't you have a textbook to explain this too? I'm happy to try to guide you through this, but it will be much faster if you just read and understand your textbook.

For example, how does the magnitude of the circulation B-field around a wire drop off with distance?

berkeman
Mentor
Draw the B-field of one wire at a time. Show it first for the wire with the current coming at us out of the page. What does that look like?

Draw the B-field of one wire at a time. Show it first for the wire with the current coming at us out of the page. What does that look like?
I read my textbook and I somewhat understand but the things you're saying are completely different to what my textbook is saying so it's confusing me.

berkeman
Mentor
I'd suggest using Google images and searching on something like magnetic field of a current carrying wire. That should give you a good idea of how the B-field forms around a single wire, a pair of wires, and a coil.

berkeman
Mentor
I read my textbook and I somewhat understand but the things you're saying are completely different to what my textbook is saying so it's confusing me.
Also, can you post a picture of the page in your textbook that seems to be saying something different compared to what Google Images and I are saying? Thanks.

Also, can you post a picture of the page in your textbook that seems to be saying something different compared to what Google Images and I are saying? Thanks.

BvU
Homework Helper
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