In 1966, scientist Valerii Vinokur developed a theory regarding the Hall effect, which states that when a material is subjected to a magnetic field, its voltage points in a certain direction based on the field’s orientation and the material’s current. Vinokur’s theory posited that the Hall effect essentially reverses with materials that become superconductors, meaning the positive end of the superconductor will become negative. The theory was unconfirmed until a team of Harvard researchers developed a bismuth-based, ultra-thin superconductor material that they used to confirm it.Which choice best states the main idea of the text?Researchers have obtained the most definitive evidence to date of the reversal of the Hall effect with regard to superconductors. eliminateResearchers have identified an innovative new method for working with superconductors.eliminateBismuth is the most important of the components required to examine the impacts of superconductors and magnetic fields. eliminateIt’s difficult to understand superconductors because of the confusion put forth by the controversial Hall effect.

The term ordinary Hall effect can be used to distinguish the effect described in the introduction from a related effect which occurs across a void or hole in a semiconductor or metal plate when current is injected via contacts that lie on the boundary or edge of the void. The charge then flows outside the void, within the metal or semiconductor material. The effect becomes observable, in a perpendicular applied magnetic field, as a Hall voltage appearing on either side of a line connecting the current-contacts. It exhibits apparent sign reversal in comparison to the "ordinary" effect occurring in the simply connected specimen. It depends only on the current injected from within the void.[8

Hall Effect

What is super conductivity? How it is affected by magnetic field?

Wires carrying current in a magnetic field experience a mechanical force perpendicular to both the current and magnetic field. André-Marie Ampère in the 1820s observed this underlying mechanism that led to the discovery of the Hall effect.[3] However it was not until a solid mathematical basis for electromagnetism was systematized by James Clerk Maxwell's "On Physical Lines of Force" (published in 1861–1862) that details of the interaction between magnets and electric current could be understood.

Wires carrying current in a magnetic field experience a mechanical force perpendicular to both the current and magnetic field. André-Marie Ampère in the 1820s observed this underlying mechanism that led to the discovery of the Hall effect.[3] However it was not until a solid mathematical basis for electromagnetism was systematized by James Clerk Maxwell's "On Physical Lines of Force" (published in 1861–1862) that details of the interaction between magnets and electric current could be understood.Edwin Hall then explored the question of whether magnetic fields interacted with the conductors or the electric current, and reasoned that if the force was specifically acting on the current, it should crowd current to one side of the wire, producing a small measurable voltage.[3] In 1879, he discovered this Hall effect while he was working on his doctoral degree at Johns Hopkins University in Baltimore, Maryland.[4] Eighteen years before the electron was discovered, his measurements of the tiny effect produced in the apparatus he used were an experimental tour de force, published under the