I'm a high school student. I love computers and electronics. Few weeks ago, I thought to build my own electronic gadget but, unfortunately I had not much knowledge in electronics. So, I decided to learn. After Googling here and there, I came across a large amount of information. Nothing, except one thing, that daunts and intimidates me is that what the term Charge means? None of the books tell what it means. Some tell that it is the basic property of the matter and just it and don't define further about it. Whereas some don't even bother to tell about it. On Wikipedia it is defined as:
Electric charge is the physical property of matter that causes it to experience a force when close to other electrically charged matter.
The definition is quite bit difficult and confusing. Similarly from All About Circuits Website tutorials I got a different type of definition and understanding.
From books, I came to know that we still don't know much about charges even great scientists like Sir Stephen Hawking doesn't known much about it. Is it correct?
If not, then why was it written in the books (I mean here books not a book), what is its correct definition? Why majority of books don't define what charges is/are?
Best Answer
Like Ali said, charge is a property (or characteristic or feature) of a particle. The particle could be an atom, or it could just be a part of an atom like an electron or a proton.
Unfortunately, we can't really say much about why particles have this property, or what causes this property to exist. We can only describe some things we observe about this property that we call charge.
Charge comes in two types, which we arbitrarily label as "positive" and "negative".
Positive charges repel each other with a force that we can measure, negative charges repel each other similarly, and opposite charges attract each other.
We find that there are components of atoms called "protons" and "electrons" that are always positively and negatively charged, respectively.
Charge is conserved. That means, in all the experiments we have tried, the difference between the amount of positive and negative charge in a closed system is the same at the end of the experiment as it was at the beginning of the experiment, and we therefore believe this is true of all closed systems in the universe.
Even though we don't know what charge is or where it originally comes from, the description of what it does is enough for us to predict lots of useful things and make lots of useful tools like radios and computers.