Register to reply

Finding Voltage in a Circuit

by salman213
Tags: circuit, voltage
Share this thread:
salman213
#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
Experts defend operational earthquake forecasting, counter critiques
EU urged to convert TV frequencies to mobile broadband
Sierra Nevada freshwater runoff could drop 26 percent by 2100
blochwave
#2
Feb21-08, 08:39 PM
P: 288
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
#3
Feb21-08, 09:19 PM
P: 303
the answer for v1 = 20 V

not 40 V

so hmmmmmmmm

blochwave
#4
Feb21-08, 10:37 PM
P: 288
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
#5
Feb22-08, 06:11 PM
Sci Advisor
PF Gold
dlgoff's Avatar
P: 2,726
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