What is the resistance of gold?
As the graph shows, the resistivity of a substance is very much dependent on temperature. For most conductors, resistivity increases with rising temperature. At 20 °C, the resistivity of gold is approximately 2.44 × 10−8 ohm-m and steadily rises with increasing temperature.
Electrical or thermal condutivity, resistivity, density and melting point
|TIBTECH||Electrical conductivity (10.E6 Siemens/m)||Electrical resistivity (10.E-8 Ohm.m)|
- Metal particles are held together by strong metallic bonds, which is why they have high melting and boiling points. The free electrons in metals can move through the metal, allowing metals to conduct electricity. Superconductors have little or no electrical resistance.
- Resistance of a conductor is the obstruction offered by the conductor in the flow of current through it. It is measured by the potential difference needed across the conductor to flow one ampere current through it. The resistance of a conductor depends upon its material, temperature, length and area of cross section.
- Surely, upon an increase in temperature, the atoms within the thermistor would vibrate with more energy and therefore more vigorously, hence making the electrons flowing through the electric circuit more likely to collide with one of the atoms, so increasing resistance.
The electrical resistivity of a material is also known as its specific electrical resistance. It is a measure of how strongly a material opposes the flow of electric current. A definition of resistivity is the electrical resistance per unit length and per unit of cross-sectional area.
- More resistance means less current is flowing through the circuit. Equivalent resistance is a different way of indicating 'total' resistance, which we calculate differently for series and parallel circuits. In a series circuit, the different components are connected in a single, continuous loop.
- The electrical resistivity of a material is also known as its specific electrical resistance. It is a measure of how strongly a material opposes the flow of electric current. A definition of resistivity is the electrical resistance per unit length and per unit of cross-sectional area.
- The SI unit of electrical resistivity is the ohm⋅metre (Ω⋅m). It is commonly represented by the Greek letter ρ, rho. Although the SI resistivity unit, the ohms metre is generally used, sometimes figures will be seen described in terms of ohms centimetres, Ω⋅cm.
Aluminum is lighter than copper. Aluminum has a resistivity varying from 2.65 to 2.82 × 10−8 Ω · m. Combined with it's light weight and alloyed with some other metals to make it stronger, aluminum is ideal for electrical cables.
- The unit of resistivity is then ohm-meters (Ωm). Nichrome, a non-magnetic alloy that is commonly made up of 80% nickel and 20% chromium, has a resistivity ranging from 1.10 × 10−6 Ωm to 1.50 × 10−6 Ωm (0.00000110 Ωm to 0.00000150 Ωm) and a very high boiling point (~1400 °C).
- Copper is considered to be a conductor because it “conducts” the electron current or flow of electrons fairly easily. Most metals are considered to be good conductors of electrical current. Aluminum and most other metals do not conduct electricity quite as good as copper.
- The resistance-change factor per degree Celsius of temperature change is called the temperature coefficient of resistance. This factor is represented by the Greek lower-case letter “alpha” (α). A positive coefficient for a material means that its resistance increases with an increase in temperature.
Updated: 16th October 2019