How Do You Calculate Resistance in a Series Circuit?

[lazyboy92]

_________300ma__
|...... |
|...... ∏ L1
_ +......| R1
9v......|........ ignore the dots in the middle
- -...... ∏ L2
|......| 2R
|________________|

Find the:

The value of R

The total resistance

and any other answers this question might yield

Thanks a lot.

only question i got wrong in a test. :(

 

[drkidd22]

300ma = 9/R
Total Resistance = 30Ohms

30/2 = 15ohms each resistor?

 

[Redbelly98]

_________300ma__
|...... |
|...... ∏ L1
_ +......| R1
9v......|...... ... ignore the dots in the middle
- -...... ∏ L2
|......| 2R
|________________|

Find the:

The value of R

The total resistance

and any other answers this question might yield

Thanks a lot.

only question i got wrong in a test. :(

I am redrawing the circuit, hopefully this is easier to look at:

 ________300ma__
|               |
|               ∏ L1   
_ +             |  R1      
9v              |
- -             ∏ L2
|               |  2R
|_______________|

Are you sure you reproduced the question accurately? It's weird to have those inductors in there, without for example a switch that closes at time t=0 or something along those lines. Also, is the 300 mA the current at some specific time, or after a long time has passed?

Also, did you mean to say 2R or R2 in the figure?

300ma = 9/R
Total Resistance = 30Ohms

30/2 = 15ohms each resistor?

If R were 300 ohms, then the current would be 9/300≠0.3A.

 

[drkidd22]

If R were 300 ohms, then the current would be 9/300≠0.3A.

I mean 30 Ohms, the O makes it look like a 300

 

[rdl]

I am happy to assist with your question on series circuits.

Firstly, to find the value of R, we can use Ohm's Law, which states that resistance (R) is equal to voltage (V) divided by current (I). In this case, we know the voltage (9V) and current (300mA or 0.3A), so we can rearrange the equation to solve for R.

R = V/I
R = 9V/0.3A
R = 30Ω

Therefore, the value of R is 30Ω.

To find the total resistance in this circuit, we need to add up the individual resistances. In a series circuit, the total resistance is equal to the sum of all the resistances. In this case, we have R1, R2, and 2R (since L2 and R2 are in parallel, we can combine them into one equivalent resistance).

Total resistance = R1 + 2R + R2
Total resistance = 30Ω + 2(30Ω) + 30Ω
Total resistance = 30Ω + 60Ω + 30Ω
Total resistance = 120Ω

Therefore, the total resistance in this circuit is 120Ω.

Additionally, this circuit may yield other answers such as the total current (since we know the voltage and total resistance, we can use Ohm's Law to find the current) and the voltage drops across each component (since we know the current and resistance of each component, we can use Ohm's Law to find the voltage drop).

I hope this helps and good luck on your future tests! Remember to always double check your calculations and use the appropriate formulas for each situation.