# Left or Right hand rule?

I'm currently looking at the right hand rule for magnetism, and have got myself a bit mixed up. I was originally taught to use the left hand rule, with the acronym FBI: Force for the thumb, B field for the first finger, and current for the middle finger.

Since current flows in the opposite direction to electrons, shouldn't this work for magnetic forces on moving partciles? Yet all my textbooks use the right hand rule.

A summary of which rule is appropriate for which case would be ideal!

• Your left hand rule works for negatively charged particles. For positively charged particles or conventional current use the right hand rule. – garyp Mar 26 '18 at 17:14

# Fleming's Right Hand Rule:

It is for electromagnetic induction, that is, current being induced by a varying magnetic flux. An application is an AC generator.

Your "FBI"acronym will work appropriately. Just remember that $I$ is the induced current.

# Fleming's Left Hand Rule:

It is for Force on a charged particle (or conductor) placed in a magnetic field. An application is a DC motor.

"FBI" will work here too. $F$ is the force on the charged particle or the conductor.

# Right Hand Palm Rule:

Used for finding direction of magnetic field around a conductor.

If you point your thumb towards the direction of flow of current, then the direction of curl of the other fingers will indicate the direction of magnetic field lines.

Both your left hand rule and the more common right hand rule are correct.

You can use any of the rules.The Right Hand Rule is generally applied on a charge moving in magnetic field while Flemings Left Hand Rule is used in case of motors and current carrying conductors in magnetic field.