# Recent content by franktherabbit

1. ### Engineering Find the total work in a circuit

Well the difference in the capacitor energies is: ##ΔE_c=(frac{1}{2}(Q_o+q)^C_1+\frac{1}{2}(q)^2/C_2)-\frac{1}{2}(Q_o)^2/C_1=-150uJ## The work of the generator is ##Eq=-100uJ## Since ##-250uJ## wasnt's correct i guess the equation is ##ΔE=ΔE_c-Eq=-50uJ## but why is it ##-Eq## we are subtracting...
2. ### Engineering Find the total work in a circuit

I can't think of a way to do it.. Is at least a) and b) correct?
3. ### Engineering Find the total work in a circuit

Homework Statement This is a problem from some textbook a friend emailed me: The text goes like this: When the switch is open the charge on ##C1## equals ##Q_o=40uC## and ##C_2## has no charge on it. The switch closes and some charge ##q## flows through the capacitors (suppose the flow to be...
4. ### Delta-Y transformation of resistors

Ohhh, i see now, i had this all wrong. Turns out algebra is the killer here. Thanks man! :D
5. ### Delta-Y transformation of resistors

Sure, :). ##R_1=\frac{R_{12}*R_{31}}{R_{12}+R_{23}+R_{31}}## ##G_1=\frac{1/G_{12}+1/G_{23}+1/G_{31}}{1/G_{12}*1/G_{31}}## ##G_1=\frac{(G_{12}+G_{23}+G_{31})/(G_{12}*G_{23}*G_{31})}{1/(G_{12}*G_{31})}## ##G_1=\frac{G_{12}+G_{23}+G_{31}}{G_{23}}## See it? :)
6. ### Delta-Y transformation of resistors

Homework Statement Starting from the expression of the Delta-Y resistor transformation work out the conductance transformation equation. Homework Equations 3. The Attempt at a Solution [/B] I will just be using one equation as others are done analogically. My Δ has ##(R_{12},R_{23},R_{13})##...
7. ### Engineering Transformation of resistors in a circuit

Would you like me to post the full problem solution so you can see if we got something wrong since it does equal to the solution from the book?
8. ### Engineering Transformation of resistors in a circuit

Sure, here it is: And here is the original text: "The switch is open in state 1 and then it closes. During the time until the stationary condition appears, ##+2uC## of charge flows through the wire with ##C_1## Calculate the amount that goes through the wire with ##C_2##." Using this...
9. ### Engineering Transformation of resistors in a circuit

Homework Statement From the circuit diagram ( http://postimg.org/image/lldnr7mf7/ ) calculate the net charge flown through the capacitor 2. Homework Equations 3. The Attempt at a Solution [/B] I actually don't need to solve the full problem as i understand how, what i have trouble with is the...
10. ### Find the limit of the expression

So, ##\ln u=\ln \left(\frac{n^2+2n+1}{n^2+2n+3}\right)^{\frac{2n^2}{n+1}}## ##\ln u=\frac{2n^2}{n+1}\ln \left(\frac{n^2+2n+1}{n^2+2n+3}\right)## ##\lim_{n\to\infty}\ln u=\lim_{n\to\infty}\frac{2n^2}{n+1}\ln \left(\frac{n^2+2n+1}{n^2+2n+3}\right)## ##\lim_{n\to\infty}\ln...
11. ### Find the limit of the expression

Homework Statement $$\lim_{x\to\infty} \left(\frac{n^2+2n+1}{n^2+2n+3}\right)^{\frac{2n^2}{n+1}}$$ Homework Equations 3. The Attempt at a Solution [/B] I tried ##\lim_{x\to\infty} \left(\frac{n^2+2n+3-2}{n^2+2n+3}\right)^{\frac{2n^2}{n+1}}=## ##\lim_{x\to\infty}...
12. ### Determining the capacitance of the two conductors

Homework Statement For a given system, a conducting cylinder with radius ##r=a## with a linear charge density ##Q'## and a conducting surface at a distance ##z=h## from the cylinder, calculate the linear capacitance of the cylinder.Take that ##h>>a## ##C'=\frac{Q'}{U}## Homework Equations 3...
13. ### ,,Why are you wearing that stupid man suit?''

,,Why are you wearing that stupid man suit?''