Related Concept Videos

Specific Heat01:16

Specific Heat

The specific heat capacity of a substance refers to the energy required to increase the temperature of one gram of that substance by one degree Celcius. Specific heat capacity is often represented in calories (cal), grams (g), and degrees Celsius (oC), but can also be expressed in joules (J), kilograms (kg), and Kelvin (K), among other units.
For example, increasing the temperature of one gram of water by 1°C requires one calorie of heat energy and can be written as 1 cal/g-°C, or 4186 J/kg/K.
Superconductor01:24

Superconductor

A substance that reaches superconductivity, a state in which magnetic fields cannot penetrate, and there is no electrical resistance, is referred to as a superconductor. In 1911, Heike Kamerlingh Onnes of Leiden University, a Dutch physicist, observed a relation between the temperature and the resistance of the element mercury. The mercury sample was then cooled in liquid helium to study the linear dependence of resistance on temperature. It was observed that, as the temperature decreased, the...
Types Of Superconductors01:28

Types Of Superconductors

A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
Heat Flow and Specific Heat01:12

Heat Flow and Specific Heat

Heat is a type of energy transfer that is caused by a temperature difference, and it can change the temperature of an object. Since heat is a form of energy, its SI unit is the joule (J). Another common unit of energy often used for heat is the calorie (cal), which is defined as the energy needed to change the temperature of 1 g of water by 1 °C, specifically between 14.5 °C and 15.5 °C, since the energy needed shows a slight temperature dependence. Another commonly used unit is the kilocalorie...
The Y-to-Delta Circuit01:19

The Y-to-Delta Circuit

A balanced wye-to-delta circuit comprises balanced Y-connected voltage sources and delta-connected loads with no neutral line connection.
The initial step in analyzing a wye-to-delta circuit is to assume a positive phase sequence. These phase voltages are then utilized to calculate the line voltages that occur directly across the delta-connected load impedances. Van, Vbn, and Vcn are the phase voltages in wye, and Vab, Vbc, and Vca are the line voltages for a delta circuit. The relation between...
The Delta-to-Y Circuit01:16

The Delta-to-Y Circuit

In the delta-wye circuit, the source is delta-connected, while the load is in a wye configuration. This means that the phase voltage of the delta-connected source is equal to the line voltage of the wye-connected load. The connection between two-line currents originates from the delta-connected source. The phase difference in the balanced system allows for calculating one line current given the other, utilizing the positive sequence of phases. In the delta-wye system, the phase currents in the...