# Left and Right Hand Rules - Physics

• scorpa
In summary, the left hand rule is for electron flow, the right hand rule is for conventional current, and if you dont know which is which, use the direction of current that flows in the direction of the charge carriers.
scorpa
Hello Everyone,

I am having trouble with the left and right hand rules in Physics. If anyone could explain them to me with as much detail as possible I would really appreciate it. I can tell you what I know and some of what I would like to know if it helps:

The left hand is used for electron flow. Electrons flow from negative to positive and this is the direction that your thumb should point. Your fingers curl up and over the wires to give you the direction of the magnetic field.

The right hand is used for conventional current which flows from positive to negative, your thumb points in the direction of this. Your fingers curl up and over the wires to give you the directoin of the magnetic field.

Here is some of what I want to know. How do you tell which end of the wire is north and south? When is it best to use what rule? And anything else you can give me, I am so lost right now

When you know what type of current it is, use the correct hand. Thats all there is to it.

But how do you figure out which end of a wire is north and which is south?

Wires don't have a north end or south end.. the problem will tell you that current is flowing in a direciton, if it says the current is electrons, then use the left hand, if its the ocnventional current, use the right hand.

If its from a circuit diagram, then decipher the current flow from the configuration of the circuit, namely the EMF.

Forget left hand rules. Always use the direction of conventional current, and remember that if the charge carriers are negative the conventional current flows the opposite direction to the way the charges move.

the right hand rule is for EM induction, and left hand is the motor rule. Always use conventional current for both.

## 1. What are the Left and Right Hand Rules in Physics?

The Left and Right Hand Rules are a set of rules used to determine the direction of a magnetic field, electric current, or force in a given situation. They are based on the principle of the right-hand rule, which states that the direction of a vector can be determined by curling the fingers of the right hand in the direction of rotation and the thumb will point in the direction of the vector.

## 2. What is the Left Hand Rule used for?

The Left Hand Rule is used to determine the direction of the magnetic field around a current-carrying wire. It states that if the left hand is held with the thumb, index finger, and middle finger forming a 90-degree angle, with the index finger pointing in the direction of the current, then the thumb will point in the direction of the magnetic field.

## 3. How is the Right Hand Rule used in Physics?

The Right Hand Rule is used to determine the direction of a magnetic force on a moving charged particle. It states that if the right hand is held with the index finger pointing in the direction of the magnetic field, the middle finger pointing in the direction of the particle's velocity, then the thumb will point in the direction of the magnetic force.

## 4. What is the difference between the Left and Right Hand Rules?

The Left and Right Hand Rules are essentially the same, except for the orientation of the hand used. The Left Hand Rule is used for determining the direction of the magnetic field, while the Right Hand Rule is used for determining the direction of the magnetic force. Additionally, the Left Hand Rule uses the left hand, while the Right Hand Rule uses the right hand.

## 5. How are the Left and Right Hand Rules applied in real-life situations?

The Left and Right Hand Rules are used in various real-life situations, such as in motors, generators, and transformers, where the direction of the magnetic field or force is important. They are also used in understanding the behavior of charged particles in particle accelerators and in the design of magnetic resonance imaging (MRI) machines.

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