Hi guys. First time caller here. Before getting into my question I just want to say how much I love both the philosophy and content of this site. A new human age of information and technology is dawning - in the way of how we learn and share - and you guys are leading the charge. New realms of understanding and possibilities are opening up before me, and for that I thank you. ... I could gush and kiss ass all day, but let's move on.
Ok, if it isn't clear from the thread topic, I'm having trouble with Question 20 of the Simultaneous Equations worksheet. My grasp on the algebraic concept of solving systems of equations is strong, but time and time again I come up with resistor values different from the answers given. I'm plugging in the same approach I used successfully in questions 15 - 17, so I'm thinking maybe my understanding of how the use of a rheostat affects voltage is lacking - by which I mean the fact that R2 is connected to the circuit both as a fixed resistor and by the variable wiper. It seems like the electricity would follow "path of least resistance," but is there some crazy double voltage / parallel voodoo at work here? I'd love to think that the given answers are wrong, but since I didn't find any other posts on this, it seems unlikely [and all the more personally deflating =( ] Here are the equations I'm using:
Given that R = Rtotal (Vr / Vtotal).....
R1 = (R1 + R2 + 10K) (30/100)
&
R2 = (R1 + R2 + 10K) (40/100)
I'd appreciate any insight you guys could offer. I'm just going in circles at this point.
Ok, if it isn't clear from the thread topic, I'm having trouble with Question 20 of the Simultaneous Equations worksheet. My grasp on the algebraic concept of solving systems of equations is strong, but time and time again I come up with resistor values different from the answers given. I'm plugging in the same approach I used successfully in questions 15 - 17, so I'm thinking maybe my understanding of how the use of a rheostat affects voltage is lacking - by which I mean the fact that R2 is connected to the circuit both as a fixed resistor and by the variable wiper. It seems like the electricity would follow "path of least resistance," but is there some crazy double voltage / parallel voodoo at work here? I'd love to think that the given answers are wrong, but since I didn't find any other posts on this, it seems unlikely [and all the more personally deflating =( ] Here are the equations I'm using:
Given that R = Rtotal (Vr / Vtotal).....
R1 = (R1 + R2 + 10K) (30/100)
&
R2 = (R1 + R2 + 10K) (40/100)
I'd appreciate any insight you guys could offer. I'm just going in circles at this point.