It is a useful term when exploring the mathematical formula for parallel Mathematically, conductance is the reciprocal of resistance, and each 1/R term in the pure reactances, one could convert each reactance (X) to a susceptance (B ), then. tower configuration of a three-phase overhead transmission line. The parameters computed are the resistance R, reactance X, susceptance B, and conductance. It is calculated as a ratio of the potential difference (voltage) between two points of the circuit to the current that runs through the circuit. Electrical resistance is.
Also like conductance, susceptance is a scalar quantity. When resistive and reactive components are interconnected, their combined effects can no longer be analyzed with scalar quantities of resistance R and reactance X. Likewise, figures of conductance G and susceptance B are most useful in circuits where the two types of opposition are not mixed, i.
In order to express and quantify the effects of mixed resistive and reactive components, we had to have a new term: To be consistent, we need a complementary measure representing the reciprocal of impedance. The name for this measure is admittance. Admittance is measured in guess what? Positive susceptance values indicate capacitance, so the correct choice is c. In the RX half-plane, we'll never see a vector pointing toward the left of the vertical axis, either upward or downward.
Online Electrical Admittance Calculator
The correct choice here is d"None of the above"! We have a coil with a reactance of j20 ohms. The susceptance in siemens equals the reciprocal of the reactance in ohms. When we want to find the reciprocal of an imaginary number, we must take the reciprocal of the real-number coefficient and then change the sign. The reciprocal of 20 is 0. The correct answer is b. The flash in a xenon flash tube circled in red occurs after the gas is ionized, when its electrical resistance is reduced The Physics of Resistance in Gases and Uses for It Under normal conditions gases are great dielectrics because they have a very small number of charge carriers such as positively charged ions and electrons.
This property of gases is used in contact switches, overhead power lines, and air-gap capacitors, because air is a mix of gases and its electric resistance is very large. Gases have ionic conductance, and because of it when an external electric field is acting upon the gases, their resistance slowly decreases. This is a result of the increase of ionization of molecules.
As the voltage increases, a glow discharge occurs and the resistance becomes more closely dependent on the voltage. This property of gases was used in the past in gas lights called stabistors for stabilizing the DC for a wide range of currents. As the external voltage further increases, the discharge in the gas becomes a corona discharge, the resistance drops more, and the discharge turns into an electric spark.
As this happens, an equivalent of a small lightning occurs and the resistance of the gas around the lightning drops to a minimum. Its operation depends on the ionization of the gas inside of it through collision, when gamma ray photons enter it.
The resulting rapid decrease of resistance is registered by the control circuit. The property of ionized gases to glow when a small electric current flows through them is widely used in neon lighting for advertising, for displaying the electromagnetic field neon voltage testersand in sodium-vapor lamps used for lightning.
Energy saving compact fluorescent lamps work on the same principle due to the ability of mercury vapors to glow in the ultraviolet spectrum. The light of the visible spectrum is produced by the conversion of the ultraviolet radiation into visible light in a phosphor coating, which covers the inside of the lamp.
Similarly to semiconductors, resistance of gases is non-linear and depends on the external electric field. Their resistance is determined by the concentration of ions of different polarity.Conductance, Susceptance and Admittance in Series AC Circuit
These ions are atoms or molecules that either lost or gained electrons. In the former case they are called cations, and in the latter case — anions. When we place two electrodes with opposite charge inside an electrolyte and thus create an external electric field, cations and anions start moving. The mechanism of this process is based on the charging and the loss of charge of a given electrode.
Anions give away extra electrons on the anode, and cations gain the missing electrons on the cathode. A plastic shower head is electroplated with chrome. We can see a thin red layer of copper on the inner side that is not plated with chrome. A significant difference between electrolytes and metals, semiconductors, and gases is the movement of particles of the electrolytes within them.
It is widely used in medicine and technology, from refining metals by filtering out impurities to introduction of medicine into a given area of the body through electrophoresis. We owe our shiny bathtubs and faucets to electroplating — a process of covering surfaces with metals, chrome and nickel in this case.
The quality of electroplating depends on the temperature and resistance of the electrolyte, in which the process runs, as well as on other parameters. From the perspective of physics, our body is an electrolyte and we have to remember it when it comes to personal safety, in particular with regards to resistance and the electric current running through the body. We should note that the lie detector works by measuring the resistance on different areas of the skin. It is believed to aid with determining which questions are uncomfortable for the interviewee, when used in conjunction with other physiological measurements.
Many people prefer the so called tube sound. Vacuum is the ideal dielectric. What resistance could we possibly talk about in vacuum? Well, thanks to one of the less popular works of Albert Einstein compared to his famous work on relativitythe one that considers the work performed by electrons separating from a metal, using resistance in vacuum, we can now create a number of electronic devices that have been serving mankind since the early days of electrical and RF engineering.
Two-electrode vacuum devices have different resistance when polarity of the applied voltage changes.
Electrical Admittance - Inverse of Impedance
Until the s, they were used for rectification of alternating current. Vacuum tubes with three or more electrodes were used to amplify signals. Now they are replaced by more energy efficient transistors. However vacuum tubes are still used in the industry. X-ray tubes and magnetrons which are used in radars, are vacuum tubes.