Questions tagged [electrical-resistance]

The tag applies to electrical resistance and resistors. DO NOT USE THIS TAG for non-electrical resistance.

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Why is contact resistance proportional to $\frac{1}{\sqrt{F}}$ not $\frac{1}{F}$?

See pages 13-15 in "Electrical Contacts: Principles and Applications" for reference. Imagine the following system: Two flat, but rough, surfaces of the same finite area $A$ being brought together. ...
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Resistance and temperature mathematical relationship of a thermistor

When I did an experiment measuring the Resistance of a thermistor as I increase or decrease the temperature, when I plot the resistance (y - axis) against temperature (x-axis), I get an exponential ...
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Voltage Change Across a Resistor/Circuit

Say you have a 9 volt battery, and you connect the two ends of the battery with a wire to form a circuit with no resistor. If you measure the potential difference between the two ends of the battery, ...
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What if I keep holding a household battery?

I have a question in my mind. What if I keep holding a Duracell(1.5V Battery) touching both the terminals with my fingertips? Will the circuit be completed and the battery drain? Or will it have no ...
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What will be the equivalent resistance of this circuit? [on hold]

What will be it's equivalent resistance
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Confusion in usage of formulae for power dissipated in a circuit

When should we use $\frac {V^2}{R}$ and when to use $I^2R$. Because many times they ask about the power without giving details about series and parallel. I am really confused
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Does temperature coefficient of resistance depend on geometry?

By temperature coefficient of resistance of a material about a reference point $T_0$, I mean $${1\over R(T_0)} \left.{dR\over dT}\right|_{T_0}.$$ All the sources (that I’ve seen) that quote this ...
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Why Does a Resistor's Resistance Vary?

Whenever we try to measure the resistance in a multimeter, the value is not the same for all measurements. Slight variations are observed over several measurements. But why this happens? And can this ...
63 views

What are the correct current directions? [closed]

i have a problem in my text book asking me to find the equivalent resistance of this circuit : so i used kirchhoff's first law and drew some abitritary current directions : the two 6 ohm resistors ...
61 views

Can we add the resistivity due to different scattering mechanisms?

Suppose there's a metal in which electrons interact with themselves and with the phonons. The hamiltonian might look like this \begin{equation} H= \sum_{k}\epsilon_k c^\dagger_k c_k + \sum_{k}\...
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Solving resistance using symmetry

Recently I've been studying current electricity and I saw many books using symmetry to solve circuits. broadly categorised as left/right symmetry and up/down symmetry where we take current to be ...
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How relative positions of battery and galvanometer affect the sensitivity of a wheatstone bridge?

I know one of the factors that affect the sensitivity of the galvanometer is the relative magnitudes of the resistances in the four arms of the bridge. the bridge is most sensitive when all the four ...
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It is possible that without resistance current flow a conductor [closed]

It is possible that without resistance current flow a conductor (answer with proof by)
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“Directional” conductivity in linear flux-potential laws?

Question: Has the notion of "directional conductivity" been defined and used in the study of heat flow and electric current flow? Context: The table below gives three laws that describe linear flux-...