B Why is the test charge always positive?

AI Thread Summary
The discussion centers on the use of positive test charges in educational contexts, primarily for simplicity and consistency. While test charges can be either positive or negative, many educational resources opt for positive charges to minimize confusion for learners. Using a positive test charge allows for easier comparison of electric field effects without complicating the directional aspects of forces. This approach aids in teaching and helps students grasp fundamental concepts before introducing more complex scenarios. Overall, the preference for positive test charges is rooted in didactic considerations.
misbah alshaybani
Messages
1
Reaction score
0
why test charge is always positive ?
 

Attachments

  • تنزيل.jpg
    تنزيل.jpg
    6.4 KB · Views: 179
Physics news on Phys.org
It isn't always positive. It generally has an arbitrary value, which can be positive or negative.
 
Could be your book/course uses always a positive test charge for consistency. The less changes in the system, the easier it is to compare the differences with the earlier cases, that makes teaching/learning easier.
 
Borek said:
Could be your book/course uses always a positive test charge for consistency.

I always use positive test charges when I teach, for simplicity. Negative test charge gives E vector in opposite direction than Coulomb force on it, which per se is not a problem, but you know, didactics :smile: When someone is learning about it for the first time it's better to avoid such things, we can come back to it later.
 
Reply
  • Like
Likes misbah alshaybani, berkeman, topsquark and 2 others

Thread 'Need help understanding particle physics and quantum physics'

So I know that electrons are fundamental, there's no 'material' that makes them up, it's like talking about a colour itself rather than a car or a flower. Now protons and neutrons and quarks and whatever other stuff is there fundamentally, I want someone to kind of teach me these, I have a lot of questions that books might not give the answer in the way I understand. Thanks
View full post »

Similar threads

B Questions about the Universe: Positive & negative fields and effects
Replies
4
Views
4K
B Where Do Electrons Go When a Battery Loses Charge?
Replies
22
Views
6K
I Why charge density of moving dipole is dependent on time?
Replies
3
Views
2K
I Maxwell's equations and the momentum of charge
Replies
12
Views
3K
B Why can't gravity be just a form of magnetic attraction?
Replies
6
Views
4K
I NASA is seeking a faster, cheaper way to bring Mars samples to Earth
Replies
6
Views
2K
Why Does Positive Charge Exert Elec. Field Beyond Neg. Charge?
Replies
16
Views
2K
B How did fundamental charge thinking develop?
Replies
2
Views
3K
B A couple of questions about diodes and the depletion region
Replies
9
Views
3K
A Relativity: Test charge moving perpendicular to a current carrying wire exhibits a force
Replies
7
Views
1K

Hot Threads

Recent Insights

Back
Top