Hi, I am massively confused with what resistance is and how it applies to circuits and would be very grateful if someone could help. I know this sounds like a basic question but I have been reading for hours and the more I read the less it makes sense. My book says that resistance is 'the property of a material which makes moving charges dissipate their energy'. It talks about the electrons in a wire interacting with the atomic lattice of the material resulting in electrons transferring their energy to the lattice.(adsbygoogle = window.adsbygoogle || []).push({});

If you now consider two very simple circuits each of which has the same source voltage of 6V; one has a 10 ohm resistor and the other has a 30 ohm resistor. According to my book the 30 ohm resistor has a greater tendency to dissipate the energy of the charges. However, the voltage drop across each resistor is the same (6V) therefore each coulomb of charge will dissipate 6J of energy. So if each unit of charge has no choice except to dissipate 6J of energy then how can this be a definition of resistance as each unit of charge is dissipating the same amount of energy? My book also says electrons gain kinetic energy from voltage source and transfer this energy by colliding with the lattice. But wouldn't this mean that when the electrons pass the resistor they would have zero kinetic energy?

Finally, I know that the current in the circuit with the 30 ohm resistor will be less but what causes this specifically as I don't see how you can explain the slowing down of current AND the transfer of energy with the same information - i.e. interactions with the atomic lattice.

Any help is much appreciated!

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# Resistance & Electrical Circuits

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