Calculating Current and Voltage in a Series Resistor Circuit

In summary, when calculating current and voltage in a series resistor circuit, you can use Ohm's Law to determine the current by dividing the voltage by the total resistance of the circuit. The voltage drops across each resistor in a series circuit and the total voltage of the circuit is equal to the sum of the individual voltages. Additionally, the current remains constant throughout the circuit, but the voltage may vary depending on the resistance of each individual resistor. By understanding the relationship between current, voltage, and resistance, you can accurately calculate and predict the behavior of a series resistor circuit.
  • #1
Midas_Touch
|------A------|
|.....* R2
- Vs.....|B
-.....|
|.....* R1
|------C----- |

Assuming that the above is a circuit (sorry for the bad drawing, ignore the dots), what would be Ia, Ib, Ic (currents), Va, Vb, Vc (voltages)? Initially, I thought that the current and the voltage would be the same at all points.

I know that Req is equal to the sum of R1 and R2 (resistance). So would Ia be Vs/(R1*R2)? Would Ib be Vs/R2? and Ic, Vs/R1?

For the voltages, I think that it is equal to Vs at points A,B,C. But, I am not sure.

I'd appreciate some feedback. Thanks.
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
In a series circiut the current is the same at all points, not the voltage. Use Ohms law to find the voltage at each point, given the constant current. Your total voltage drop should equal the source voltage.
 
  • #3
Interestingly you are using two correct concepts, but not applied to the correct variable.

It is the voltage (potential) that starts off at a value (Vs) and in a series circuit, drops some amount through each component, until it reaches its lowest value (typically ground = 0v).

The other variable current, in a series arrangement, does not drop but stays the same through each component.

This will be different in a parallel arrangement, and I will let you figure that one out.. Applying what I gave you above, try this one again..
 
Last edited:
  • #4
Integral said:
In a series circiut the current is the same at all points, not the voltage. Use Ohms law to find the voltage at each point, given the constant current. Your total voltage drop should equal the source voltage.

How about if R2 was parallel to R1? Would the current still be the same and the voltage be different at points around the circuit?
 
  • #5
Midas_Touch said:
How about if R2 was parallel to R1? Would the current still be the same and the voltage be different at points around the circuit?
See my last post, and you should be able to deduce your answer.
 
  • #6
Midas_Touch said:
How about if R2 was parallel to R1? Would the current still be the same and the voltage be different at points around the circuit?
If R2 were parallel to R1 then it would not be a series circuit would it? Why do you expect a parallel circuit to behave the same as a series?
 

FAQ: Calculating Current and Voltage in a Series Resistor Circuit

How do I calculate the total resistance in a series resistor circuit?

In a series resistor circuit, the total resistance is equal to the sum of all individual resistances. This means that you simply add up the values of each resistor in the circuit to get the total resistance.

What is the formula for calculating the current in a series resistor circuit?

The formula for calculating the current in a series resistor circuit is I = V/R, where I is the current in amps, V is the voltage in volts, and R is the total resistance in ohms.

How do I find the voltage drop across each resistor in a series circuit?

The voltage drop across each resistor in a series circuit is equal to the current multiplied by the resistance of that specific resistor. This can be represented by the formula V = IR, where V is the voltage drop, I is the current, and R is the resistance.

What is the relationship between current and resistance in a series circuit?

In a series circuit, the current is directly proportional to the resistance. This means that as the resistance increases, the current decreases, and vice versa. This can be seen in the formula I = V/R, where an increase in resistance results in a decrease in current.

Can I use Ohm's Law to calculate the voltage in a series resistor circuit?

Yes, Ohm's Law can be used to calculate the voltage in a series resistor circuit. The formula V = IR can be rearranged to solve for V, so if you know the current and resistance, you can use Ohm's Law to find the voltage in the circuit.

Similar threads

Finding the Current in a Resistor in a Closed Circuit
Replies
4
Views
2K
How to calculate R1 and R2 in this RC circuit
Replies
3
Views
2K
Understanding Voltage Drop in a Circuit
Replies
10
Views
1K
Why is it important to classify circuits as series or parallel?
Replies
5
Views
2K
RCL series circuit analysis: Damping Constant
Replies
1
Views
391
Calculate voltage over capacitor and resistance
Replies
7
Views
665
Ohm's Law - Finding Source Voltage
Replies
3
Views
1K
Voltage, Current, and Resistance Calculations
Replies
13
Views
2K
RC Circuit with parallel resistor
Replies
6
Views
2K
Finding an open-cicuit voltage, why is resistor in series ignored?
Replies
2
Views
985

Hot Threads

Recent Insights

Back
Top