# Right Hand Rule

I'm trying to solve problems about magnetic fields of electric currents induced by charged particles and wires. Most of these problems require the right hand rule, which I don't really understand. All I know is your thumb points in the direction of the current and your fingers curl in the direction of the magnetic field. I don't understand how to tell if the magnetic field is going into the page or out of the page based on this.

Question 1: The figure shows 2 charged particles moving in opposite directions. What is the direction of the magnetic field at point P? I attempted to copy the figure but the forum keeps editing it so I'll describe it: there are 2 positive particles separated by a distance (d). One is moving to the right, the other to the left. Halfway between the particles is point P (kind of like below, the plus signs represent positive particles with P halfway between).

(+)
l
l
P
l
l
(+)

Answer: Both particles make magnetic fields that point into the page.

I know this is the correct answer, but I don't get how to do this? How can you tell if the magnetic field is into or out of the page?

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vela
Staff Emeritus
Homework Helper
What specifically is it about applying the right-hand rule that is confusing you? Your textbook will likely give you as good of an explanation as you're going to get here.

PeterO
Homework Helper
I'm trying to solve problems about magnetic fields of electric currents induced by charged particles and wires. Most of these problems require the right hand rule, which I don't really understand. All I know is your thumb points in the direction of the current and your fingers curl in the direction of the magnetic field. I don't understand how to tell if the magnetic field is going into the page or out of the page based on this.

Question 1: The figure shows 2 charged particles moving in opposite directions. What is the direction of the magnetic field at point P? I attempted to copy the figure but the forum keeps editing it so I'll describe it: there are 2 positive particles separated by a distance (d). One is moving to the right, the other to the left. Halfway between the particles is point P (kind of like below, the plus signs represent positive particles with P halfway between).

(+)
l
l
P
l
l
(+)

Answer: Both particles make magnetic fields that point into the page.

I know this is the correct answer, but I don't get how to do this? How can you tell if the magnetic field is into or out of the page?
Draw a line across your page,
Now hold your hand with thumb pointing left, with that line directly under your thumb. Your fingers curl such that they will be curling into-the-page above your thumb - ie further up the page than the line - but out-of-the-page below our thumb - ie further down the page than the line.