The voltage tag has no wiki summary.
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1answer
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Why does the area of the plates affect the capacitance?
Why does the area of the plates affect the capacitance? Lets say I have a parallel plate capacitor with a charge of 10C and a potential difference of 5V. By the definition $C=Q/V$, the capacitance is ...
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1answer
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About the electrostatic voltage
What's the difference between electrostatic voltage and normal voltage, like the battery's voltage.
How to calculate the charge on a charged plate if we knew its electrostatic voltage?
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1answer
79 views
Which of these two methods is correct for calculating current?
I recently came across a question, for which I saw two possible methods of finding the solution. I was required to calculate the "current flowing" $I$ when given the voltage $V$, frequency $f$, total ...
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0answers
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What works on 8-10 volts, 4 milli amps, and is not hardwired? [closed]
I want to know what is the smallest device that can work on a few milli amps? I know a NE-2 neon bulb works on less than 10 mAmp but on 90 volts at least.
I need to find a small device that:
1- ...
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2answers
308 views
Voltage and current of positive lightning
For a physics issues investigation I chose to investigate what effects lightning could have on an aeroplane while in flight if it was struck and then go on to discuss some possible implications of ...
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What is the principle of active voltage balancing/equalizing device?
I am wondering about active voltage sharing devices. Their purpose is to equally divide voltages on slightly unequal super-capacitors. I found some papers like this, but it is too scientific.
I want ...
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1answer
299 views
how to calculate electric relative permittivity of fluid or medium
I am confusing in calculating permittivity of the fluid. Permittivity differs from one fluid to another.
$$\varepsilon=\varepsilon_r\varepsilon_0$$
Since it is an electrical property combined with ...
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1answer
85 views
How electrons act under rotating magnetic field?
I study Power Engineering in University. Today I asked my lecturer to explain me exactly how atom's electrons act under spinning rotor's magnetic field, that generated dynamic electricity. But he even ...
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1answer
73 views
Calculate Capacitance in Series AC Circuits?
I'm supposed to calculate the capacitance of an unknown capacitor in series, but I'm not sure exactly which equation to use.
I know the voltage across the resistor (Vr), voltage across the capacitor ...
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3answers
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Why do we use Root Mean Square (RMS) values when talking about AC voltage
What makes it a good idea to use RMS rather than peak values of current and voltage when we talk about or compute with AC signals.
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2answers
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Out of phase voltage current source and resulting power
Examining the following graph, I am trying to understand the power plot. The power appears to take on a negative value when the current changes direction or the voltage changes polarity. Negative ...
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6answers
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Difference between current and voltage sources
I am confused about the current and voltage. My intuitive example would be that of a pipe of say water. The diameter of the pipe determines the amount of water flowing per second but the pressure is ...
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0answers
43 views
Object accelerated by electromagnet
If I have an electromagnet (powered by a battery) and a metallic object, the
power generated will depend on the voltage of the battery and the resistance of the coil.
If I accelerate the object, will ...
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1answer
62 views
Should the electric potential of a positively charged sphere be negative?
Because the indefinite integral of the electric field results in a negative value? (As the function is proportional to $r^{-2}$?
I've got to be missing something... Help please!! Thanks!
Also, I ...
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3answers
3k views
Why do birds, sitting on electric wires, not get shocked?
If we would touch electric wires, we would get a shock, even if we are not touching ground (so that no connection is complete form wire to ground through us). I always see that birds sit on electric ...
