# 2 Q's: Super Position and Series-Parallel

#### Otis

Joined Dec 10, 2009
6
#1
Super Position
I know i have to short one source and solve, then short the other and solve, but then Im lost.
I must find Vr2 to answer question. #2
Classic Series-Parallel
Just a large question for me, i got as far as finding Resistance total, which i think is 312.62Ω, but i could be wrong.
The question asks for VRx R1 - R6, IRx R1 - R6, Current Total, Power Total, and Resistance Total. (r1=15Ω,r2=100,r3=100,r4=1000,r5=150,r6=100)

Any help is greatly appreciated, thanks in advance.

#### zgozvrm

Joined Oct 24, 2009
115
For #2, your total resistance is incorrect.

This may help some:

2 resistors are in series only if there is no connection branching off between them. Therefore R3 and R6 are NOT in series, since R4 is also connected to the link between R3 and R6.

2 resistors are in parallel if the ends of the 1st resistor are DIRECTLY connected to the ends of the 2nd resistor (no other resistor can be connected between the leads). Therefore, R2 and R4 are NOT parallel, since although the bottom leads are directly connected to each other, the top leads are connected by a 3rd resistor (R3).

#### ronak67

Joined Dec 10, 2009
6
for the first problem
the answer can be 350/3 volts.
by shorting the 150v supply the voltage across r2 is 100/3 volt.
by shorting the 100 v supply the voltage across r2 is 250/3 volt.
so in total the voltage across r2 is 350/3 volt.
I hope it is right.

#### zgozvrm

Joined Oct 24, 2009
115
for the first problem
the answer can be 350/3 volts.
by shorting the 150v supply the voltage across r2 is 100/3 volt.
by shorting the 100 v supply the voltage across r2 is 250/3 volt.
so in total the voltage across r2 is 350/3 volt.
I hope it is right.
I got 100/3 V = 33.33 V and 150/3 V = 50 V, for a total of 250/3 V = 83.33 V