Recent content by theuserman

Just completeness, I'm going to prove that: \nabla \times (\nabla \times \vec{v}) = \nabla(\nabla \cdot \vec{v}) - \nabla^2\vec{v} So we have \nabla \times (\nabla \times \vec{v}) = \partial_i(\nabla \times \vec{v})_j \epsilon_{ijk} = \partial_i(\partial_l v_m...

Hi. Regarding this question, my friend said all you have to do is use Example 2.1 and substitute L for a/2 and z for \sqrt{z^{2} + (\frac {a} {2})^{2}} This gives the right answer... I understand the substitution for L however the substitution for z I can't get. Anyone care to shed some...

Here's an image.

Hey all, I have a diode clamper (1 diode) and I had to use a capacitor in lab to smooth out the output (the input was a triangle wave - without the capacitor the output was still a bit triangular at the tips). This is just curiosity - can anyone explain to me how the capacitor managed to smooth...

Phrak, Thanks for the tip with \epsilon , as for your first suggestion it makes sense to make it i... Since it is a dummy variable. Thanks.

Some new equations I need to prove and have no idea how to go about it... I'll show what I've attempted so far. a) \nabla (\vec{A} \cdot \vec{B}) = \vec{A} \times (\nabla \times \vec{B}) + \vec{B} \times (\nabla \times \vec{A}) + (\vec{A} \cdot \nabla)\vec{B} + (\vec{B} \cdot \nabla) \vec{A}...

I've also posted this in the Physics forum as it applies to some physical aspects as well. --- I want to know if I'm on the right track here. I'm asked to prove the following. a) \nabla \cdot (\vec{A} \times \vec{B}) = \vec{B} \cdot (\nabla \times \vec{A}) - \vec{A} \cdot (\nabla \times...

I was thinking, since I'm constrained to use 10 V batteries what if I made some voltage dividers and stuck the output voltages where I want the specialized batteries to be? Essentially fashion a 5.(whatever) battery out of a 10 V battery and put 110 Ohm resistor as the load resistor and 140 Ohm...

I suppose, but that wouldn't give me exactly 5 V... would it? Are you just suggesting I stack the diodes?

Hey everyone, I need some help with this problem. A triangular wave generator produces a waveform (triangular wave with peaks of 10 V). I need to develop a circuit that clips the voltages at 5 V (ie, they become flat at 5V). We're allowed to use DC voltages of +10 V and −10 V as well as...