hmmmn , ok then ..back to the drawing board .

 

Consider a very simple case.

I get a bunch of resistors and sort them into bins based the color markings. I then pull two resistors out of the 1 kΩ bin and put them in series with a 20 V supply. I'm therefore expecting to see 10 V across each one and to have a total current of 10 mA. But it turns out that I only get about 2 mA of current and one resistor has ten times the voltage drop across it as the other. What is the most likely cause of the problem?

Consider the same case but this time I get nearly 20 mA of current and, again, one resistor has 10x the voltage across it as the other. What is the most likely problem?

 

Consider a very simple case.

I get a bunch of resistors and sort them into bins based the color markings. I then pull two resistors out of the 1 kΩ bin and put them in series with a 20 V supply. I'm therefore expecting to see 10 V across each one and to have a total current of 10 mA. But it turns out that I only get about 2 mA of current and one resistor has ten times the voltage drop across it as the other. What is the most likely cause of the problem?

Consider the same case but this time I get nearly 20 mA of current and, again, one resistor has 10x the voltage across it as the other. What is the most likely problem?

Consider a very simple case.

I get a bunch of resistors and sort them into bins based the color markings. I then pull two resistors out of the 1 kΩ bin and put them in series with a 20 V supply. I'm therefore expecting to see 10 V across each one and to have a total current of 10 mA. But it turns out that I only get about 2 mA of current and one resistor has ten times the voltage drop across it as the other. What is the most likely cause of the problem?

Consider the same case but this time I get nearly 20 mA of current and, again, one resistor has 10x the voltage across it as the other. What is the most likely problem?

Ah Ha ...the resistor, Right on Bahn ! thanks man for breaking it down for me , I'm going to have to work through more circuit problems in the book...get more familiar with sequence of operations to help to see these problems more clearly ..

 

r1 voltage drop (270)(0.0154)=4.158
r2 voltage drop (570)(0.0154)=7.854
=12.012
r3 voltage drop(470)(0.015)=7.238
r4 voltage drop(330)(0.0154)=5.082
=12.32

You need to be more careful in your calculations. How can the current in R3 and R4 be different? You're dropping units in your calculations; which you shouldn't do until you have a better grasp of fundamentals.

the sum of the applied voltage drop in a series circuit must equal the applied voltage . so still not sure on why e2 is o v ?

Troubleshooting circuits such as the one you were given requires you to use more than just formulas to understand why you're getting the values given. Strong analytical skills are a requirement to be a technician or engineer.

You were told that the total current is 15mA. You calculated the current in R3 and R4 to be 15mA. Again, what does Kirchhoff's Current Law tell you?

 

You need to be more careful in your calculations. How can the current in R3 and R4 be different? You're dropping units in your calculations; which you shouldn't do until you have a better grasp of fundamentals.
Troubleshooting circuits such as the one you were given requires you to use more than just formulas to understand why you're getting the values given. Strong analytical skills are a requirement to be a technician or engineer.

You were told that the total current is 15mA. You calculated the current in R3 and R4 to be 15mA. Again, what does Kirchhoff's Current Law tell you?

I agree my skills are not so good.......yet , I will brush up on kerchhoffs current law again and keep studying on my circuits , glad for the motivation to keep me aligned . thx

 

I will brush up on kerchhoffs current law

Using KCL, can you write the equation for \( \small I_T\) in terms of \( \small I_1\) and \( \small I_3\)?

 

I'd pay extra attention to the fact that the total current is 15mA. That would give you your total resistance. Is this an explain your reasoning answer?

 

hmmmn , ok then ..back to the drawing board .

Hi,

I am happy to see that you did not give up. Once you do a few of these problems you get much better at it. The first one will always be the hardest to do and that's with almost anything.

A final question from me would be, why is there a 'poll' at the start of this thread. Not only is it not needed, both possible answers are the same

 

Hi,

I am happy to see that you did not give up. Once you do a few of these problems you get much better at it. The first one will always be the hardest to do and that's with almost anything.

A final question from me would be, why is there a 'poll' at the start of this thread. Not only is it not needed, both possible answers are the same

Thanks for the help MrAl , I just started this class so I'm trying to get a handle on the correct ways to use all the formulas & laws , we have class/theory one night & lab the next night so most of my time to learn this is on my own from the book at home and with all of the great people on this forum , as far as the poll I'm not sure why that's there ? I'll see if I can remove it?