/sci/ - Science & Math

>>5722804
The open circuit 20mV and short circuit 100uV are normal. You're picking up stray electrical fields from mains wiring and internal thermal noise. Some of that might even be radio waves. If you want it calibrated, you need to send it off to Fluke, unless you have laboratory grade voltage standards available. Even then some digital multi-meters use EEPROM to store offsets. The best thing is to buy (I know, buyfag) another good meter. Hook up the new meter and your old one to the same variable power supply (battery and a variable resistor voltage divider would be close enough) and check the old Fluke against the new meter for any differences. Imaged ripped from a Google image search

>>5708217
I believe you're confusing "mass" with "weight.

>>5673196
OP or Christopher Langan?

Just thought of this. It's what I said in fewer words:
He's either the smartest of the dumb, or the dumbest of the smart.

>>5672985
The only thing he's good at is using his intellect in trying to connect unsubstantiated proofs to mathematical proofs by using the slimmest of causality as a smoking gun. Any truther, anti-vax, bigfoot researcher, new age medicine, fundamentalist, Yuri Geller wanna be, etc. always ignores the obvious proof for the mundane that fits their agenda, and never consider the alternative, i.e. I do the anti elephant dance every morning in Kansas and there's been no elephant attacks.

>>5662975
I intend to live forever. So far, so good.

Is OP still here?

>>5626576
Oops. Should have added in how I calculated it:
((220 || 150)+(33)) || 100
220 || 150=89.1892
89.1892+33=122.1892
122.1892 || 100=54.9933

>>5626576
I still get 54.9933 ohms. I'm doing the top circuit, the one without the battery. Also, OP said the lower circuit is misdrawn and the two resistors are really connected to -18V.

>>5626555
It's just Ohm's Law. The only thing you could be confused about is how to simplify the resistors in the circuit. Is there any specific part that confuses you? Are you confused as to where you start?

I'm slightly confused here. Schematic "A" has a 150 and a 100 ohm resistor. Are they floating or connected to -18V? According to the question on the paper, "Rl" is equivalent to the resistor network on the top of the page. If you find out what this combined resistance is, the rest is just Ohm's Law, assuming when he asks for the "V,I, and P" of "Rl". The value of the resistor network for "A" is about 54.9933 ohms. The value of the resistor network for "B" is about 199.9007 ohms.

>>5567005
It's a simple voltage divider. All "R" are the same resistance. The resistor that connects to point "A" does not factor into the equation because an "ideal voltmeter" is a meter that has infinite resistance and doesn't load the circuit.

>>5560200
Oops. Wanted to add:
The current in the collector is the same as the current in the emitter minus the base current. Minor oversight on my part. Sorry.

>>5560200
Yes. Due to the nature of the circuit, both matched transistors are fed the exact same current, and have the exact same current gain, and have the same current flowing through each collector-emitter.

>>5560154
Ic of Q2 is the same as Ic of Q1. Remember, Q1 and Q2 are matched pairs, and the base current for both transistors are split equally giving the same current gain for both transistors. To calculate the V drop of R2, use the known collector current of Q1. I*R=V

>>5560116
Yes.
The Vbe of Q1 will be the same as Vbe of Q2. Any current trying to go into the base of Q2 will split in half and go into the base of Q1. If heat causes the Vbe of Q1 to get smaller, the same heat will cause the Vbe of Q2 to do the same. If something causes the gain of the transistors to change, one transistor will null the changes in the other transistor.

>>5559876
Imagine if Q1 were removed. Due to the gain of Q2, a voltage drop will occur across R2. If Vcc or the temperature is changed, the gain of Q2 will change and the Vdrop on R2 will change. Now imagine you add Q1 back in. Q1 is matched to Q2. Q1 takes half of the current from the base of Q2. As the Vcc or temperature changes, the gain on Q1 will counter act the changes in Q2.

>>5553309
Stab him in the chins.

>>5552563
I've had no problems doing that. I just take a signal I can use (like the signal heading into the amp), use an op-amp with some resistors and capacitors to make an audio filter, and drive some LED's. Maybe even drive an LED VU meter from each channel.

Evolution is a race, not a finish line.

>>5542953
Let me try and explain.
Imagine you have two magic containers. One container has a bunch of electrons and the other doesn't. Since electrons don't like being cramped up, they want to spread out to the other container. If you add more electrons, they have a bigger desire to spread out. If the electrons are sitting there, that's a measure of voltage. Now we add a pipe (load) that allows electrons to move to the other container. If we count the number of electrons per second traveling through the pipe, that's a measure of current. Bigger pipes (more load) can move more electrons in less time. Power is the amount of work done and is calculated P=VI. If you have voltage and no current, or if you have current with no voltage, you have no work (power) being done.

>>5529856
It's easy to travel back in time. Just grab a telescope.

Death only becomes interesting after life becomes boring.

>>5512838
Both would be bad. If the water is conductive enough to "grab" a strike, it's conductive enough. Even though electrons a really small, get enough together and they'll do anything they damn well want.