So how much current is flowing in R2 and R3?Man , i knew that should of sticked with my gut feeling.
Voltage in parallel stays the same.
So voltage across R2 & R3 is 0 volts
Hey phantomvs, when you "removed" R2 from the circuit, you turned R2 into an open circuit/branch, and applied the behaviour of open circuits (current is 0 and resistance is infinite) to solving the problem... But the instructions ask you to do the exact opposite: short R2, don't open it. What is the basic behaviour of a short circuit? That is, what is the value of current in ANY short circuit?View attachment 99374
I am stuck on this question, that asks me the following :
If R2 is short circuited , the amps in R3 is : ?
Here is what i did :
I redrew circuit without R2.
What am i doing wrong ?
We are going round and round.Ok , i am real sorry about this....I am really testing your patience
This is still bugging me.
I have been doing some reading
http://www.allaboutcircuits.com/textbook/direct-current/chpt-5/component-failure-analysis/
So what i have jotted dowm is the following.
So i shorted R2.
I get R1 at 6 volts and 0.6 Amps
R2 becomes 24 volts at 0 Amps
since R3 also becomes shorted R3 becomes 24 volts at 0 amps.
Any of this logic good ? Or am i way way off again ?
I can't keep track of the various problems here. Does this problem have a short across R2 or not?If this is not right someone explain this to me
I
You need to do the one thing that you haven't done yet -- draw the modified circuit.Ok guys, i don't like to give up. I am REALLLY sorry about this. I am REALLY trying to understand this.
So this is what i know so far.
In original question i posted .. I said IF R2 is shorted what is amps in R3 ?
Now i know that in a parallel circuit voltage remains the same.
Current is split in the branches and equals the total current of circuit.
Series circuit current is the same throught circuit and voltage varies but sum of all voltage equals supply voltage.
Now i learned that a "short" across a resistor is equal to replacing the resistor with a straight piece of wire.
From what i see in the circuit is that i have 30 volts as my power..
It hits the first resistor in series so would give me 30v on R1 with 3 amps of current. Using V=IxR
Now where i am stuck is if R2 is "short circuited" why does R3 short as well.
I am guessing its the increase of amps on R3 kills it or cause its in parallel with R2 ?
Cause doesn't current take the path of least resistance.
So shouldn't just go to R2 to get to the other side 0v
Parallel BranchYou need to do the one thing that you haven't done yet -- draw the modified circuit.
Consider the case below in which the red line is the wire. Which case below ?
Is it shorting R2 or R3? In my original diagram it Shorts R2
Again -- what is a wire other than a zero ohm resistor? A conductor or a jumper
Regardless of the current flowing through a zero ohm resistor, what is the voltage across it? 0 Volts
By definition, components in parallel have the same voltage across them. Since R2, R3, and the short are in parallel, they have the same voltage across them.
So what must the voltage be across both R2 and R3? 0 Volts
Given that voltage, what must the current through both R2 and R3 be? 3 Amps
Therefore, any current that enters the node on the right must go through which branch?
Ooops!!! Pls tell me if this is yet another big hole in my knowledge... The way I remember this type of problem being explained in class is (of course the jumper wire will have 3 Amperes but) that compared to the zero resistance in the jumper wire/short, the resistance of R2 and R3 and any other paralleled resistor, would be so great that it might as well be infinite, so the current will always only pass through the jumper or the short. So we had to redraw that part of the circuit with only the jumper / red wire in your diagram, no more R2 and R3. In effect the only resistance left in the system is R1.Given that voltage, what must the current through both R2 and R3 be? 3 Amps
I don't see any problem with your knowledge -- this is the line of reasoning that I am trying to lead the TS to one step at a time. My concern now is that, by spelling it out, the TS will read your answer, think it makes sense, but not really grasp it and, given another similar problem (say on an exam) will not be able to work it because they didn't earn it themselves and so something still hasn't clicked in THEIR knowledge of the topic. That is why we don't just supply answers in Homework Help, but rather try to lead the TS into figuring it out for themselves.Ooops!!! Pls tell me if this is yet another big hole in my knowledge... The way I remember this type of problem being explained in class is (of course the jumper wire will have 3 Amperes but) that compared to the zero resistance in the jumper wire/short, the resistance of R2 and R3 and any other paralleled resistor, would be so great that it might as well be infinite, so the current will always only pass through the jumper or the short. So we had to redraw that part of the circuit with only the jumper / red wire in your diagram, no more R2 and R3. In effect the only resistance left in the system is R1.
If I encountered the TS question in an exam I would have answered : R2 and R3 no longer exist because of the short, but that branch now has 3 amperes.