Finding Voltage in a Circuit


by salman213
Tags: circuit, voltage
salman213
salman213 is offline
#1
Feb21-08, 08:29 PM
P: 303
1. I made a quick sketch

Find V1 and V2






3. Is there an easier way to do this question without applying mesh analysis, because this question was in my chapter 2 (intro to KVL/KCL), but i cannot think of a way to find this unless i use mesh analysis. Any advice
Phys.Org News Partner Science news on Phys.org
NASA's space station Robonaut finally getting legs
Free the seed: OSSI nurtures growing plants without patent barriers
Going nuts? Turkey looks to pistachios to heat new eco-city
blochwave
blochwave is offline
#2
Feb21-08, 08:39 PM
P: 289
Well assuming I'm doing it right of course, you wouldn't need any simultaneous equations or anything, that'd be over complicating it, just need KCL really

so at the node above the 20 and 5 k resistors(or the equivalent 4k resistor!)you have 10 milliamps flowing in, and you need 10 mA flowing out, obtained with a voltage drop across that 4 k of just V=IR=10*4=40 Volts

You can check to see that puts 8 mA across the 5 k resistor and 2 across the 20 k, for a total of 10 mA
salman213
salman213 is offline
#3
Feb21-08, 09:19 PM
P: 303
the answer for v1 = 20 V

not 40 V

so hmmmmmmmm

blochwave
blochwave is offline
#4
Feb21-08, 10:37 PM
P: 289

Finding Voltage in a Circuit


ok, so what you basically have are two resistors in series, and those two resistors(with eq. resistance of 4k) are in parallel with the other two resistors which I mentioned have an equiv. resistance of 4k as well

Since they're in parallel the current splits down both paths and equal amounts both ways since the resistances are ultimately equal, sooo it's actually V=I*R=5*4=20Volts
dlgoff
dlgoff is offline
#5
Feb22-08, 06:11 PM
Sci Advisor
PF Gold
dlgoff's Avatar
P: 2,633
If you know V1, then all you need to do is "voltage-divide" to find V2.


Register to reply

Related Discussions
charge and voltage across circuit Introductory Physics Homework 10
Voltage Limiter Circuit Electrical Engineering 17
What is the voltage? AC circuit Introductory Physics Homework 2
Help on low voltage indicator circuit Electrical Engineering 6
Voltage In An Electric Circuit Introductory Physics Homework 3