How is Fleming's left hand rule applied in Hall effect

Click For Summary

Discussion Overview

The discussion centers around the application of Fleming's left hand rule in the context of the Hall effect, specifically addressing the direction of magnetic force on moving charges and the implications of charge polarity in current flow.

Discussion Character

  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant expresses confusion regarding why both positive and negative charges experience magnetic force in the same direction in the Hall effect, despite Fleming's left hand rule suggesting they should feel forces in opposite directions.
  • Another participant clarifies that while negative charges flow in one direction and positive charges in the opposite, the resulting forces on both types of charges are in the same direction when considering the overall current flow.
  • A further contribution emphasizes that Fleming's rule was developed before the discovery of electrons and is based on conventional current, suggesting that the nature of charge carriers does not affect the outcome of the force direction.
  • It is noted that if positive and negative charges are moving in the same direction, their magnetic forces would indeed act in opposite directions, but they must move in opposite directions to produce a current in the same direction.

Areas of Agreement / Disagreement

Participants exhibit some agreement on the application of Fleming's left hand rule to the Hall effect, but there remains a nuanced debate regarding the interpretation of charge movement and force direction, indicating that the discussion is not fully resolved.

Contextual Notes

There are complexities regarding the definitions of current and charge movement that may not be fully addressed, particularly in relation to the historical context of Fleming's rule and the nature of charge carriers.

Shafia Zahin
Messages
31
Reaction score
1
I've been reading the explanation of Britannica.com about the direction of magnetic force on a moving charge in hall effect.

"Whether the current is a movement of positive particles, negative particles in the opposite direction, or a mixture of the two, a perpendicular magnetic field displaces the moving electric charges in the same direction sideways at right angles to both the magnetic field and the direction of current flow."
I don't understand why does a positive and a negative charge feels the magnetic force in the same direction in the hall effect?Because as per the Fleming's left hand rule the moving positive and negative charges should feel the magnetic force in opposite directions.
 
Physics news on Phys.org
When a current is flowing, and where both + and - mobile charges are involved, the direction of the force on the negative charges (flowing in one direction) will be the same as the direction of the force on positive charges (flowing in the opposite direction). Minus times minus = plus. Flemmings rule just deals with conventional current (the rule was made long before they found electrons, ions or holes). How that current is carried makes no difference to the result.
 
  • Like
Likes   Reactions: Shafia Zahin
Shafia Zahin said:
per the Fleming's left hand rule the moving positive and negative charges should feel the magnetic force in opposite directions

If the + and - charges are moving in the same direction, the magnetic forces are indeed in opposite directions. However, the + and - charges must move in opposite directions, if the currents they produce are in the same direction. There are two "opposites": opposite charges and opposite directions.
 
  • Like
Likes   Reactions: Shafia Zahin
Okay.Thank you all for the help.
I've understood the direction problem now.
 

Similar threads

  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 24 ·
Replies
24
Views
2K
  • · Replies 8 ·
Replies
8
Views
8K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 5 ·
Replies
5
Views
1K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
13
Views
3K
  • · Replies 32 ·
2
Replies
32
Views
4K