IMPLICATIONS OF THE ABOVE HOLISTIC UNDERSTANDING OF HARMONY ON PROFESSIONAL E...
A basic Theory on Super conductors .pptx
1. SharadInstitute of Technology, College of Engineering
Yadrav- (Ichalkaranji)
(An Autonomous Institute)
Electrical Department
Class: SY
Subject : Electrical Engineering
material
Subject Code:EE405A
2. Super Conductors
• Introduction
• Properties of Superconductors
• Factors affecting superconductors
• Classification of Superconductors
• Superconductors Names
3. Introduction
“A superconductor is defined as a substance that offers
no resistance to the electric current when it becomes
colder than a critical temperature.”
Dutch physicist Heike Kamerlingh Onnes had
discovered Superconductor..
In 1911, Onnes was studying the electrical properties
of mercury in his laboratory at Leiden University in
The Netherlands when he found that the electrical
resistance in the mercury completely vanished when
he dropped the temperature to below 4.2 Kelvin —
that's just 4.2 degrees Celsius (7.56 degrees
Fahrenheit) above absolute zero.
4. Introduction
To confirm this result, Onnes applied an electric
current to a sample of supercooled mercury, then
disconnected the battery.
He found that the electric current persisted in the
mercury without decreasing, confirming the lack
of electrical resistance and opening the door to
future applications of superconductivity.
5. Properties of Superconductors
Property 1: Critical temperature/Transition temperature
The temperature below which the material changes from conductors to superconductors is
called critical temperature or transition temperature. The transition from conductors to
superconductors is sudden and complete.
Property 2: Zero Electric Resistance/Infinite Conductivity
In the superconducting state, the material has zero resistance. When the temperature of the
material is reduced below the critical temperature, its resistance suddenly reduces to zero.
Mercury is an example of a superconductor that shows zero resistance below 4 kelvin.
Property 3: Expulsion of Magnetic Field
Below the critical temperature, superconductors do not allow the magnetic field to penetrate
inside it. This phenomenon is called Meisser Effect.
6. Properties of Superconductors
.
Property 3: Expulsion of Magnetic Field
Below the critical temperature, superconductors do not allow the magnetic field to penetrate
inside it. This phenomenon is called Meisser Effect.
Property 4: Critical Magnetic Field
The certain value of the magnetic field beyond which the superconductors return to
conducting state is called the critical magnetic field. The value of the critical magnetic field
is inversely proportional to the temperature. As the temperature increases, the value of the
critical magnetic field decreases.
7. Properties of Superconductors
.
Property 3: Expulsion of Magnetic Field
Below the critical temperature, superconductors do not allow the magnetic field to penetrate
inside it. This phenomenon is called Meisser Effect.
Property 4: Critical Magnetic Field
The certain value of the magnetic field beyond which the superconductors return to
conducting state is called the critical magnetic field. The value of the critical magnetic field
is inversely proportional to the temperature. As the temperature increases, the value of the
critical magnetic field decreases.
10. Type I Superconductors
• A type I superconductor consists of
fundamental conductive elements
that are used in everything from
electrical wiring to computer
microchips. Presently, type I
superconductors have critical
temperatures between 0.000325 °K
and 7.8 °K.
• A few of the type I superconductors
need tremendous amounts of
pressure in order to achieve the
superconductive state.
• One such material is sulfur, which
needs a pressure of 9.3 million
atmospheres (9.4 x 1011 N/m2) and
a temperature of 17 °K to reach
superconductivity. Approximately
half of the elements in the periodic
table are superconductive.
Type II Superconductors
• A type II superconductor
comprises metallic
compounds such as lead or
copper.
• They achieve a
superconductive state at
much higher temperatures
compared to type I
superconductors.
• Type II superconductors can
be penetrated by a magnetic
field, whereas type I cannot.
