Why do we Call Positive Charge Positive and Negative Change Negative?

Most recent answer: 01/31/2015

Q:
What is positve and negitive change? Why do we call positive charge positive and negative change negative? ?
- Vishnu Dev (age 20)
mavelikara,kerala, India
A:

Hello Vishnu,

Positive and Negative charges are just names.   You could call them Up and Down and it wouldn't make any difference.  The laws of electricity and magnetism would be the same.   As Shakespeare said, "that which we call a rose by any other name would smell as sweet"

Benjamin Franklin who experimented with electricity in the middle 18th century made an arbitrary choice:

When a.rubber rod that is rubbed with cat's fur the charge on the rod is called negative and when a glass rod is rubbed with silk the charge on the rod is called positive.    It could have been the other way around.

LeeH

 

 

 

   
 

(published on 01/31/2015)