Physical Science 6.8b - Magnetic Force on Moving Charge

[balochan1]

are the yellow lines representing the force or the magnetic field?

[viviannaipp]

can i use the FBI rule for this?

[mephatboi]

how did u know to point ur thumb downwards (not upwards) in the 1st instance of the moving particle and upwards (not downwards) when it traveled in the opposite direction?

[mephatboi]

@mephatboi nvm, u answered it in the next video (i.e. fingers must curl in the direction of the south pole)! thx...

[DisturbedV7]

I dont understand the bit about the magnet and using the right hand rule, are your fingers not wrapped around when the actual field lines are straight?

[naruto2710]

i'm confused, do all charged particles hav a magnetic field around them; so in your last example, the charge q. so are there 2 magnetic fields interacting in that situation. what i'm trying to understand is determining the force etc when we have an interaction of magnetic fields produced by a permanent magnet and an electromagnet (i.e. from current in wire)

[knightfightnight]

A basic force field against charged partical's like the ones you find in radiation from the suns solar flares and plasma storms and certain quantum singularities so,in a way, if used with a strong enough magnetic pulse it can be used as a weak force field on space craft.cool.

[junwei520]

i like this chapter~~~

[freerider10000]

Hi, I'm just wondering why you use the Right hand rule to determine the direction of a magnetic force instead of Flemings Left hand motor rule?

From my understanding the Flemings Left hand motor rule says the First finger points along the Field direction (From N to S). The seCond finger is the Current direction (from + to -) and then the Thumb gives the direction of the Thrust (or the Force).

(Note I'm from the UK and only use Right hand Rule for generators and stick to conventional current)

[derekowens]

@freerider10000 The actual direction is a source of constant confusion because there are two ways to think of it. If you imagine the current to be positive charge flowing, what we call conventional current, then you use the right hand rule. If you imagine it to be negative charge flowing in the other direction, what we call electron flow, then you use the left hand rule. Positive charge flowing in one direction is mathematically equivalent to negative charge flowing in the other direction.

[12345Anee]

@derekowens

but Sir, that guy is asking about Flemings Left hand motor rule.....!!!!

even i m also wondering why you use the Right hand rule to determine the direction of a magnetic force instead of Flemings Left hand motor rule?

[derekowens]

@12345Anee I think I need to make a video on Flemings motor rule. I have to find some free time first, and that's pretty scarce these days...

[AceFrolic720]

@derekowens but in this video... using the LHR for the same moving positive charge,

I get a downward force.

and you said, that the LHR is only applicable to the flow of electrons.

=S

[derekowens]

@AceFrolic720 If you are thinking of the positive charge flowing, then you should use the Right Hand Rule. Positive charge flowing one way is mathematically the same as negative charge flowing the opposite way. You should get the same result for your force vector either way.

[jozozo100]

what about a charge in a magnetic field but not moving? Does anything happen then?

[derekowens]

@jozozo100 Nothing would happen. No motion, no force. A charge in an *electric* field, though, would experience a force.

[zsj382387304]

is the field inbtween two magnets uniform field?

[derekowens]

@zsj382387304 No, it's not uniform. The field lines would be curved. Similar to the field around an electric dipole.

[2Bitter2bSweet]

so is the little +ve charge like a small current element?

since i know the direction of the magnetic field im trying to find out the direction of current?? somethin like that...

[Knuffelaar1970]

I confirm that everything in this video is true.

[Adaeze611]

How do you know where the field lines point? out or in. Like the earth example, they point in...and the second one they point out...? how do I know this?

[xXCatalystic37Xx]

Why didn't you you show at the very end what direction the force would be on the charged particle? I was JUST about to confirm using the right hand rule what direction it would be. I think it would be into the screen at that orientation, being that the tangent of the magnetic field would be pointed up towards the top of the screen, the velocity is adjacent towards the left of the screen, and therefore using right hand rule the force would be into the screen.

[69kaban]

Awesome!

[Nythony]

I am sooo confused...?

[derekowens]

Yes, you certainly could use the left hand rule. If you are thinking of electron flow, that would be a good way to do it. If you are dealing with conventional current, which is the flow of positive charge, then the right hand rule might be easier.

[blitzkrieg1947]

why not use the flemming left hand law for the explaination for this?