Definition:Resistance
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Definition
Resistance is a measure of how difficult it is to pass an electric current through a conductor.
It is defined as the electromotive force needed to push a unit current through that conductor.
It is conventionally denoted $R$.
Symbol
- $R$
The usual symbol used to denote resistance is $R$.
Its $\LaTeX$ code is R
.
Dimension
The dimension of measurement of resistance is:
- $\mathsf {M L^2 T^{−3} I^{−2} }$
This derives from its definition as:
- $R = \dfrac {\text {EMF} } {\text {current} }$
Unit
The SI unit of resistance is the ohm $\Omega$: $1 \, \Omega = 1 \, \mathrm V \, \mathrm A^{-1}$
In the CGS unrationalised electromagnetic system, the base unit of resistance is the abohm $\mathrm {ab\Omega}$.
In the CGS unrationalised electrostatic system, the base unit of resistance is the statohm $\mathrm {stat\Omega}$.
Conversion Factors
\(\ds \) | \(=\) | \(\ds 1\) | ohm | |||||||||||
\(\ds \text {corresponds to}\) | \(\) | \(\ds 10^9\) | abohm (or e.m.u. of resistance) | |||||||||||
\(\ds \text {corresponds to (approximately)}\) | \(\) | \(\ds \dfrac 1 9 \times 10^{-11}\) | statohm (or e.s.u. of resistance) |
Also see
- Results about resistance can be found here.
Sources
- 1969: J.C. Anderson, D.M. Hum, B.G. Neal and J.H. Whitelaw: Data and Formulae for Engineering Students (2nd ed.) ... (previous) ... (next): $1.$ Units and Abbreviations: $1.2$ SI units $(2)$ Derived units