Recent content by x86

1. Confusion about circuit schematic notations

Thanks for all the replies, I was just confused about the symbols. I've just always assumed that symbol meant an ideal voltage source. The solution is rather trivial if we assume an ideal voltage source and ideal diodes, namely Vo(t) = 0 for Vi(t) > 0 Vo(t) = -0.41Vi(t) otherwise To earlier...
2. Confusion about circuit schematic notations

Maybe they could take a bunch of electrons, put them by the - terminal, surround it by an insulating material, then doing something similar to the + terminal, except taking electrons away?
3. Confusion about circuit schematic notations

This solved my question. Now something long plaguing me (that I knew at the back of my head, but had no confirmation of) has been resolved!
4. Confusion about circuit schematic notations

Ah ok, so this symbol means there is a voltage source between those two nodes, with current coming out of it right? But how do we know when the diagram wants this, and not an open circuit? Also, I would think the voltage source is not with respect to the ground, only that the + node is vi(t)...
5. Confusion about circuit schematic notations

I'm confused about the terminals in the picture above simply because I've seen the exact same thing mean 2 different things in schematics, namely: (1) it is an open circuit with voltage Vi(t) (2) The terminals are connected to some other circuit and thus have a voltage/current source, and the...
6. Best way to solve a system of complex equations?

I always found row reduction slower than just back-substitution. So essentially if I just do back substitution, I'll get an answer? Also, i want to express Vo in terms of Vs, so I only have two equations. If I want to solve for Vo, I'd just solve for Va, then back substitute? Oh I wish, but...
7. Best way to solve a system of complex equations?

In my circuit analysis class I consistently need to solve system of complex equations, and I can't use MATLAB or anything for it. Suppose I have the following system: (Va-Vs)/(-j15) + Va/33 + (Va-Vo)/(-j25)=0 (Vo-Va)/(-j25) + (Vo-Vs)/10 = 0 What is the best way to solve it by hand in a time...
8. (Question) Trigonometric substitution triangles

Right, but one thing kind of bugs me. Say we have x = sinp, defined on p in [-pi/2, pi/2] we then have p = arcsinx and p = arccos (sqrt(a^2-x^2) ) So there is a weird loss of information here, because whatever we put into arccos it will always output something in [0, pi/2]. So we essentially...
9. (Question) Trigonometric substitution triangles

[Prefix] When we do trigonometric substitutions (such as for the integral x^3/(a^2-x^2)^2), we say something like "let x = asinp for -pi/2 <= p <= pi/2" then we carry on and solve the integral. However, sometimes our answer is ugly and we get some term in our expression like "cosp"- so we draw...
10. Current requires a closed loop to flow in DC, not AC?

It is my general understanding that according to KCL, current requires a closed loop to flow in DC. However, this is apparently not true in AC; current doesn't needa closed loop to flow. I have drawn a circuit below which causes confusion: C1 is a charge capacitor, R1 is a resistor, I1 an...
11. Insights How I overcame learning challenges - comments

I felt the exact same way when I had to take material sciences, dynamics, and thermodynamics this semester, given that I'm not in mechanical or chemical engineering. However, you're going to have to force yourself to get excited about this content. Look in the mirror and tell yourself you...
12. Insights How I overcame learning challenges - comments

Well, I think it is important to have a rough idea of your limits before starting. I.e., It may not be wise to jump into a calculus course if you don't yet know precalc algebra and trig.
13. Insights How I overcame learning challenges - comments

Try to surround yourself with more positive people who believe in you. Changing your environment really helps, if it is possible. I've been through this before, and I can't lie, it is a tough thing to go through, especially since what they say will always be a nagging thought at the back of...
14. What exactly is moment, and when is it zero?

Ah okay. Thanks. Then it is possible for the moment at a pin to be nonzero. (However, the pin can't apply any moment to the body).
15. What exactly is moment, and when is it zero?

I am still slightly confused. is it possible for the sum of moments about a pin to not be zero?