help with Ohms

[Elizabeth767]

Find the voltage drop across each resistor in a series circuit composed of a 15 ohms and a 25 ohms resistance connected to a 100 V power supply. Voltage drop at R1 = VVoltage drop at R2 = V

 

[DerStrom8]

Hi Elizabeth767, welcome to ETO!

What have you done so far? It would be good to see your previous attempts, and it would be possible to find your mistake from there.

 

[Elizabeth767]

I do not understand this and this is a part of the beginning so if I am having issues with this then I might be in the wrong course and I just need to learn how to understand it.

 

[DerStrom8]

Okay, we'll start from the beginning. Ohm's law states that E=IR, where E is the voltage, I is the current, and R is the resistance. It's important to remember that current stays the same all throughout a series circuit--it never changes.

Voltage drop is the voltage "used up" by each resistor. You can use ohm's law to find the voltage across it if you multiply the current through the resistor by its resistance. So, the first thing you'll want to do is find the total current through the circuit. You can rearrange ohm's law to say that I=E/R. I is the total current, E is the total voltage, and R is the total resistance. Once you find I, you simply have to multiply it by each resistance to find the voltage drop across each of the resistors.

Does this make sense?

 

[KeepItSimpleStupid]

The same current, I flows through both resisors. In particular, the series combination. Can you find I?