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# R=V/I (resistance)

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1. So, in the book it says "resistance is caused by repeated collisions between charge carriers in material with each other". This implies resistance increases with number of collisions. So, if number of electrons increase, resistance increases. BUT the equation R=V/I implies resistance decreases if number of electrons increase, as current increases. Can anyone help with this?
2. From what I understood is that when the particles collide with the ions in a metal wire the temperature increases. when the temperature increase the resistance increases in order to keep the current minimum to prevent any overheating in the wire thus causing short circuits. As the number of electrons increase, there are more successful collsions which results in heat being given off thus causing the the temperature to rise. More charged particals means more current can be carried, therefore the resistance increases thus reducing the flow of charge as a result reducing the current.

I don't know if you understand tho,
3. (Original post by 123chem)
So, in the book it says "resistance is caused by repeated collisions between charge carriers in material with each other". This implies resistance increases with number of collisions. So, if number of electrons increase, resistance increases. BUT the equation R=V/I implies resistance decreases if number of electrons increase, as current increases. Can anyone help with this?
Voltage increases number of collisions since its the amount of kinetic energy each electon hss.
4. (Original post by Sunethra)
From what I understood is that when the particles collide with the ions in a metal wire the temperature increases. when the temperature increase the resistance increases in order to keep the current minimum to prevent any overheating in the wire thus causing short circuits. As the number of electrons increase, there are more successful collsions which results in heat being given off thus causing the the temperature to rise. More charged particals means more current can be carried, therefore the resistance increases thus reducing the flow of charge as a result reducing the current.

I don't know if you understand tho,
So, first, when current increases, it gets hotter, resistance gets more, which decreases current?
5. Resistance is more or less given. It basically prevents electrons from moving fast th due collision. So in a material increased resisitence means decreased speed of electrons means decreased current I.

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