Series Circuit (DC)

[Technophile]

Hello:

I'm new to the world of electronics and in the process of learning about DC circuits. My text states that increased resistance(Ω) causes a decrease in current(I). If this is the case, then why doesn't this seem to hold up in a DC circuits with the loads in series?

During the study of "in series" DC circuits, I'm suddenly told that current remains the same through out the circuit. How can this be? If I have three loads in series, it seems that the current would drop according to the amount of resistance. Please help me understand this one. I'm thoroughly confused.

 

[JimB]

I think that you are being confused by poor wording.

If there are three resistors in series in a circuit, the current flowing through each resistor is the same.

If we have a 10 volt supply, connected to a 2 ohm, a 3 ohm and a 5 ohm resistor in series, the current flowing will be 1 amp. The current is the same in each resistor.

If we now add a fourth resistor into our series chain, the current through each resistor will be the same, but it will not be 1 amp.
If the fourth resistor is 10 ohm, the current will now be 0.5 amp.

Does that help?

JimB

 

[Technophile]

I think I understand. Although the current DOES change with fluctuations in resistance, it will remain the same in all loads. That makes perfect sense to me. I think it was a combination of poor wording combined with my lack of understanding of the drawing. Thanks so much JimB, you cleared a good degree of frustration!

 

[mozly]

I feel your pain. thank you JimB