When to use the Right-Hand-Palm Rule, and not. (1 Viewer)

[currysauce]

Hello, I just wanted to know when do you use the right hand palm rule opposed to the left hand palm rule....

my teacher says its for negative charges and induced currents but i don't get it, can anyone help?!

thanks

 

[xiao1985]

right hand: when u are talkin abt positive charge/conventional current
left hand: negative charge/electron current
for the induced current, better use reasonin to deduce... if u have to use a rule then left hand ~~ but thumb pts at conventional current direction...

 

[zenger69]

you would only need to know right hand palm rule.

and thats for the motor effect - ie a current carrying wire in a magnetic field (thats the practical with two magnets and in the middle is a wire)

so when you use your right hand rule you can determine whether the wire is going up when current is passed through it or whether the wire is going down.

you know the fingers mean the way of magnetic field, wrist being your N and fingertips = south.
thumb is the direction of the current (positive to negative)
open palm is to determine the direction of the forece.

left hand rule is just when you talk about the flow of electrons.

hope it helps

 

[currysauce]

thanks guys

 

[Jaydels]

just some advice.......our class was told not to quote the right hand grip rule in an exam because its not a law or anything, its just a memory aid

 

[xiao1985]

just some advice.......our class was told not to quote the right hand grip rule in an exam because its not a law or anything, its just a memory aid

althou it is pretty hard to explain the direction of a magnetic field generated by the current carry wire... the law /eqn it uses extend beyond the scope of hsc...

 

[jumb]

Do past papers to get used to the questions. It's pretty obvious when they want you to use it.

 

[Cheezy-G]

Right Hand Palm Rule

I'll try and avoid using the left hand plam rule because that may get confusing. For positive charges, the force will be determined by the palm's direction. For negative charges, the force will be determined by the kuckles' direction. ie. If your palm is facing upwards and there is a conventional current then the direction of the force is upwards. I remember it like this:


Palm is Positive charges P
Knuckles is negative charges N or Kn
It works all the time

Hope that helps

 

[Iron_Scarecrow]

Yes that usually works best, no need to bring in the left hand at all.

 

[m_isk]

or you know that the right hand rule relies on CONVENTIONAL current...so if we're talkling electron flow, then the direction of the conventional current is in the opposite direction

 

[JumboKHS]

or you know that the right hand rule relies on CONVENTIONAL current...so if we're talkling electron flow, then the direction of the conventional current is in the opposite direction

Yep thats what i do, when its a negatively charged particle moving i just put the direction of my thumb in the opposite direction to its movement.