New answers tagged voltage
2
Yes, this would be a fair assessment of how the circuit is probably working.
As a bit of an advisory, do not use the shower until you have traced the source of this!. It takes about 1mA for you to feel a tingling. Assuming it was dry when you were changing the light, then your resistance would be around 1-20kOhm in a damp environment (like a shower). This ...
2
The rate of change of voltage with respect to current is known as the dynamic resistance. The ratio of voltage to current at a point is the static resistance.
For an ohmic circuit element, the static resistance and the dynamic resistance are equal.
For non-linear circuit elements, the dynamic resistance is more useful as one can then linearize the element ...
2
Because there are lots of variables having some impact on resistivity (like temperature), in non-linear resistive materials the resistivity can be also a function of provided current or voltage, there is need to have true function combining voltage drop and current value on the material, like I = f(U). Because sometimes this function is strongly non-linear ...
1
Ohm's Law is indeed V = IR, which means the resistance is R = V/I.
This article defines resistance of an ideal conductor as having the potential difference being proportional to the current through it.
There are a multitude of online articles about this, including this Ohm's Law calculator.
1
but what is R in this formula?
Since you're interested in what happens after the switch opens in both cases, redraw the circuit after the switch opens.
In (1), there is just the one resistor R to the left of the switch so that's the resistance in the time constant.
In (2), there is just the two series connected 1k resistors so R = 2k is the resistance ...
2
Have derived it myself:
$${\tau}=\dfrac{\underbrace {\large { I}}_{\text{through inductor at steady state}}}{\underbrace {{dI_{\small }}/{dt}}_{\text{initial}}}$$
Also $$V_{\text{inductor}}=L\dfrac{dI}{dt}$$
where $I$ is current through inductor.
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Re your edit 1, if the system consisted solely of plates B and C you would be correct: the opposing charges would create an electric field (and potential difference) between them that would cause charge to flow.
However, there is more to the system than plates B and C. In particular, the charge on plate A creates an electric field that exactly cancels that ...
1
then why is there no potential difference between the two capacitors
It's not quite clear what you mean here but do understand that charged capacitors are electrically neutral.
When a capacitor is "charged", it is not electrically charged, it is energy charged in the same sense as when we say a battery is charged.
There is nothing mysterious about two ...
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Bear in mind that capacitance is a function of Area and distance between plates,
Connecting all the capacitance in series effectively increase the distance between the plates
thus decreasing the total capacitance under the same voltage
When connecting them in parallel, across the same voltage but the effective area is increased, therefore the capacitance ...
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In reality you are not able to connect anything in parallel. There are always resistances and (for AC) capacitances and inductances that cause voltage drops. So connecting two sources will cause current flow from one battery with higher voltage to the other making a voltage drop on the wire. This current can be very high, but it is never infinite, as it ...
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Firstly, I am assuming these batteries to be DC, otherwise this solution is wrong:
If you connect multiple batteries to a circuit, their polarity makes all the difference. If they are opposite in polarity then the battery with lower voltage will charge. A diagram will help to elaborate the question if you are talking about a specific arrangement.
If the ...
0
A more "straight" answer to your question, is:
Q = V x C, = V x (K A/d). Q = charge; V = voltage, C = capacitance; K = permittivity constant; A = surface area holding the charge; d = distance between the surfaces holding the charge.
The formula changes, depending on the shape of the surfaces - parallel plates, cylinders, spheres, etc. and any dielectric ...
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