# Charge, Voltage, Current

I'm in year11 and i still don't understand the difference at all help :')
Anyone have a simple way of understanding/memorising this?
Original post by yasmins06
I'm in year11 and i still don't understand the difference at all help :')
Anyone have a simple way of understanding/memorising this?

In order to best help and follow the guidelines for posting in this forum it would be helpful if you could provide what you think each are and where is that you become confused at to the difference between the 3.
Original post by Joseph McMahon
In order to best help and follow the guidelines for posting in this forum it would be helpful if you could provide what you think each are and where is that you become confused at to the difference between the 3.

Sorry!
I know that voltage is potential difference but i dont really understand what that means, difference between what?
I know current is the actual flow of electrons.
I dont really get what charge is.
I know what they're measured in but i need help with understanding what they are in literal sense. I've watched videos and asked people but i'm still unsure.
Original post by yasmins06
Sorry!
I know that voltage is potential difference but i dont really understand what that means, difference between what?
I know current is the actual flow of electrons.
I dont really get what charge is.
I know what they're measured in but i need help with understanding what they are in literal sense. I've watched videos and asked people but i'm still unsure.

Everything in the Universe wants to move from a higher energy state to a lower energy state. The easiest example of this is that things get colder naturally not hotter (except for a few minor exceptions) this is the 2nd law of Thermodynamics. You could say that at the higher energy state they have more 'potential' than in the lower energy state and so there is a difference between the two: potential difference.

Try to apply this thing to potential difference within an electrical circuit setting.

For charge: there are 4 fundamental forces of nature, the strong and weak nuclear forces, Electromagnetic force and Gravitational. Things with mass experience a force when in a gravitational field, nucleons experience the nuclear forces (that's quite a complicated topic). You can imagine then what things experience a force when in an electric field, or what a thing must have to experience a force when in an electric field. How would reword this last point to be a standalone comment on what charge is?
Original post by Joseph McMahon
Everything in the Universe wants to move from a higher energy state to a lower energy state. The easiest example of this is that things get colder naturally not hotter (except for a few minor exceptions) this is the 2nd law of Thermodynamics. You could say that at the higher energy state they have more 'potential' than in the lower energy state and so there is a difference between the two: potential difference.

Try to apply this thing to potential difference within an electrical circuit setting.

For charge: there are 4 fundamental forces of nature, the strong and weak nuclear forces, Electromagnetic force and Gravitational. Things with mass experience a force when in a gravitational field, nucleons experience the nuclear forces (that's quite a complicated topic). You can imagine then what things experience a force when in an electric field, or what a thing must have to experience a force when in an electric field. How would reword this last point to be a standalone comment on what charge is?

Ok thank you sm, i understand voltage now.

So 'charge is needed for something to experience a force in an electric field'? Electrical field like the + and - or a battery i think, but i'm not sure i understand what kinda force.
Or is it something to do with electromagnetism?
Original post by yasmins06
Ok thank you sm, i understand voltage now.

So 'charge is needed for something to experience a force in an electric field'? Electrical field like the + and - or a battery i think, but i'm not sure i understand what kinda force.
Or is it something to do with electromagnetism?

There was a discovery made that Electric and Magnetic forces everywhere and always coexist, however, you can study Electric and Magnetic forces independently.

So yes: Charge is a property of matter such that if that matter has charge it will experience a force in an Electric field. (This is similar to "Mass is a property of matter such that if that matter has mass it will experience a force in a Gravitational Field).

We define charge as being Positive or Negative and have arbitrarily decided that Protons are Positively charged and Electrons are negatively charged (by an equal and opposite amount to the Proton i.e. they cancel each other out).

All things are made up of protons and electrons, generally atoms have equal numbers of protons are electrons and overall are neutrally charged (see my cancelling out comment). Based on this: how does something (i.e. an atom or some other body) become either positively or negatively charged?
Original post by Joseph McMahon
There was a discovery made that Electric and Magnetic forces everywhere and always coexist, however, you can study Electric and Magnetic forces independently.

So yes: Charge is a property of matter such that if that matter has charge it will experience a force in an Electric field. (This is similar to "Mass is a property of matter such that if that matter has mass it will experience a force in a Gravitational Field).

We define charge as being Positive or Negative and have arbitrarily decided that Protons are Positively charged and Electrons are negatively charged (by an equal and opposite amount to the Proton i.e. they cancel each other out).

All things are made up of protons and electrons, generally atoms have equal numbers of protons are electrons and overall are neutrally charged (see my cancelling out comment). Based on this: how does something (i.e. an atom or some other body) become either positively or negatively charged?

To become an ion an atom needs to gain or lose electrons, so i understand that it gains a charge (either positive or negative). So if a matter's atoms have a positive or negative charge they will experience a force in an electric field, for example, a circuit. Is that right?

But i dont understand what force they would experience. Is it just the force they have when they move around the circuit? But that's very similar to current, isn't it?
Original post by yasmins06
To become an ion an atom needs to gain or lose electrons, so i understand that it gains a charge (either positive or negative). So if a matter's atoms have a positive or negative charge they will experience a force in an electric field, for example, a circuit. Is that right?

But i dont understand what force they would experience. Is it just the force they have when they move around the circuit? But that's very similar to current, isn't it?

Yes: within a circuit, the charge carriers within an atom experience a force due to an electric field (once you have a complete circuit). We connect circuits via wires made of metal and so it's down to the structure of metals that there are electrons which actually move when they experience the force from the electric field.

They force they experience is liken to Mass and and Gravity i.e. what force does mass experience when in a Gravitational field? The force of gravity.

Then: what force does charge experience when in an Electric field?

As you yourself said: current is just the flow of electrons (or charger carriers as I have been using).

So: electrons move around a circuit because they experience an electric force. That movement we call 'current' and they experience an electric force because they have a property we refer to as 'charge'.

Let me know if I have over complicated.