Hi everyone, im stuck on this problem for my homework. What ive done so far is R3 = RT - R1 - R2 - R4. Also, the current total is supposedly 10ma

 

Step 1: What is the current flowing through R1?
Step 2: What is the voltage across R1?
Step 3: What is the voltage across R4?
Step 4: What is the current flowing through R4?
Step 5: What is the current flowing through R3?
Step 6: What is the voltage across R3?
Step 7: What is the resistance of R3?

 

For #1, I= V/R right? Also because this is a parallel circuit, does that make all of the voltages the same? So is it also 10ma?

 

No. You cannot make that assumption until you work through it.

R1 is in parallel with R2.
What is the equivalent resistance of R1 and R2?
What is the voltage across R1?
What is the voltage across R2?

 

Ok this is what I did.

because R1 and R2 are in parallel, I combined them to solve for R1R2

1/1000+1/1000

2/1000

1000/2

R1R2 = 500

Then I used ohms law V=IR

V=(10ma)(500)
V=0.01(500)
V=5

which applies for both because they are parallel?

 

Then because it has to add up to 10 volts, the other two are 5 volts as well?

 

View attachment 221292

From the values given in the figure, R3 cannot be determined.

 

From the values given in the figure, R3 cannot be determined.

What?!!
I can solve this while sleeping.

 

Maybe I should highlight my point.

From the values given in the figure, R3 cannot be determined.

The footnote is an addon.

...... Also, the current total is supposedly 10ma ....

 

Hi R,
Consider 10v supply at 10mA, what is the total circuit resistance.?
E

 

Hi R,
Consider 10v supply at 10mA, what is the total circuit resistance.?
E

That 10 mA is not part of the figure. It is on a footnote somewhere else.

 

From the values given in the figure, R3 cannot be determined.

As you Americans say " this is electronics 101" (whatever that means)

10V @ 10 mA is 1K resistance, so R1 and R2 make 500 ohms , therefore R3 and R4 make 500 ohms also, so R3 is ?...