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The electric field in a component is just a function of the voltage across it, and the composition of the component. So for a uniform resistor (regardless of the temperature coefficient), the electric field is $E = V/\ell$ where $\ell$ is the distance between the electrodes. Therefore, if you have two resistors in series, with resistance $R_1$ and $R_2$, as ...


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The answers are really good, but I have (as a former long-time student who has not forgotten the practicality of things) a more practical approach without considering currents or voltages, just the topology of the circuit itself: When trying to reduce a circuit, the algorithm is as follows: Any number (> 1) of resistors on the same wire. That is, no ...


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The region 1277 has the resistivity at about 200 ohms-m while 1291-1292m zone has the resistivity rising abruptly to the range of ~2k ohm-m (and later to 30k ohm-m at 1293m). By the chart below we can classify the 200 ohm-m to probably be shale while the high pike to be very resistive zone. Because this is a hydrocarbon reservoir, it is some sort of ...


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The first equation is when you want to solve for either the voltage, current, or power already knowing the other two, similar for $P=I^2R$, when you want to solve for an unknown already having knowledge of the other two. The last equation you get by noting that, $P=IV=I^2R$, hence $V=IR$ or $I=\frac{V}{R}$ plugging this into, the first equation you get ...


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The diagram is a network of wheatstone bridge, but it should satisfy the condition after which it is easy to calculate the net resistance between the points The R2 resistance will be in the middle and will be neglected if the condition of wheatstone bridge is satisfied, i.e. R1.R4=R5.R3


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It depends. The time evolution stays the same: $V(t)=V_0 e^{-5}e^{-t/\tau}$, the "non stabilized" part of the total voltage is just smaller. Often this part is considered constant for practical purposes.


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After $5 \tau$, the voltage across the capacitor is about $.7$% of what it was originally. There are definitely situations where this $.7$% could be significant, so when the problem says you can consider this voltage to be zero, it probably means that the accuracy of any tool you would use to measure the system is low enough that it wouldn't be able to ...


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In addition to Mike's answer, there are a few things that need to be noted. First, I would say that the existence of TCR is a consequence of the assumption that the resistivity is linear. It is not because the TCR is constant that the resistivity is linear. A given TCR is valid only for a specific range of temperature. Basically that is the slope of the ...


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The definition of the thermal coefficient of resistance (TCR) is the change in resistance per change in temperature divided by the resistance at a specified, fixed reference temperature: $$ \mathrm{TCR} = \frac{1}{R(T_\mathrm{ref})} \left.{\frac{\mathrm{d}R}{\mathrm{d}T}}\right|_{T=T_{ref}}. $$ Note that $R(T_\mathrm{ref})$ is a fixed value. It is the ...



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