Calculate the voltage drop.

[Montero]

Hey guys, sorry for the silly questions, but I'm very new to OHMS law.

I need to found out the voltage drop across R2:

Vs: 120 v
VD1: 25v
VD3: 67v
R1: 5Ω
R2: 5.6Ω
R3: 13.4Ω

Can someone please show me how to work this out so I don't need to be shown again? Thanks.

 

[Boncuk]

Ohm's Law

Hi Montero,

I just did only a small part of your obvious homework problem.

The questions contained in the schematic are up to you to answer properly and accurately.

You should be able to solve the rest of the problem all by yourself.

And please remember this: All forum members are willing to help and assist. What nobody will do: Making the homework for lazy students!

Boncuk

 

[KMoffett]

Montero,

There are many, many ways these components could be connected together. A schematic would be necessary to solve the problem.

Ken

 

[Boncuk]

Montero,

There are many, many ways these components could be connected together. A schematic would be necessary to solve the problem.

Ken

Objections, your honour!

There is only one way according to the values given. It is a straight series connection of three resistors with a total voltage of 120V, one resistor voltage drop of 67V and and one with a drop of 25. Just one value is missing there.

Boncuk

 

[KMoffett]

Objections, your honour!

There is only one way according to the values given.

Boncuk

This would be true if the OP had "stated" it was a straight series circuit of resistors...but he didn't. I can think of a many ways to connect 2 diodes (VD could be the drop across Zener diodes) and three resistors in series, parallel, and series-parallel combinations connected to a voltage source. That's why I asked for a schematic. Was my request inappropriate given the lack of detail?

Ken

 

[Mikebits]

In this case VD is voltage drop. ie VD1 is 25v across R1.

 

[pfofit]

If this is homework, and they are in series, then it must be day 1 of school.
Ohms law is not needed, the voltage of a third resistor is requested and two voltage drops and a source are given.

It takes way more energy to sign up and make one post than it would to read a couple pages of any basic electronics book.

tsk tsk

 

[Boncuk]

Ohm's Law

Hi Ken,

you are just thinking too complicated. Taking a close look at the values given they can only be achieved in a pure series connection of three resistors.

Especially the values 25V (voltage drop at R1) and 67V (voltage drop at R3) -no matter what the names are; they could be Vjunk1 and 3 as well - lead to that only possible conclusion without looking at a schematic.

As I already mentioned there is just one voltage value missing: voltage drop of R2 (5R6).

The OP can solve that problem with mental math - even not knowing about Ohm's Law by simply subtracting two values from another. (I won't give any more advise here not to do his homework completely.)

Looking at the problem from this point of view you will certainly agree with me.

There are people in this world who always complicate things. Just an example: A friend of mine, a highly qualified RF-engineer, had a problem with his TV. It neither displayed a video nor did it produce any sound. He opened the device and started measuring with the result that there was no mains voltage. Of course his measurement was true, because his cat had ripped the plug off the socket.

A housewife would certainly have looked for the unplugged set first.

Kind regards

Hans

 

[rjvh]

(I won't give any more advise here not to do his homework completely.)

Hi boncuk you just did

You're to good for this guy
I would response to this question as: ask your teacher why bothering me

Robert-Jan

 

[Boncuk]

Hi boncuk you just did

You're to good for this guy
I would response to this question as: ask your teacher why bothering me

Robert-Jan

Hi Robert-Jan

well, true and not true. I bet he doesn't have enough brains to grasp the help.

May be he got his homework completely done in another forum, which won't make him any wiser.

Hans