Question

The substance which possesses zero resistance at \(0 \mathrm{~K}\) is called (a) Super conductor (b) Insulator (c) Conductor (d) Semiconductor

Short answer

The substance with zero resistance at 0 K is a superconductor.

Step-by-step solution

Understanding Zero Resistance

Zero resistance is a characteristic where electrical current flows without any opposition or energy loss. This property is very specific and not exhibited by most materials under ordinary conditions.

Explanation of 0 K

Zero Kelvin (0 K) signifies absolute zero, the lowest possible temperature where all thermal motion ceases. Some materials show unique electrical properties at this temperature.

Identify Materials with Zero Resistance at 0 K

At 0 Kelvin, certain materials transition into a state where they exhibit zero electrical resistance. These materials can conduct electricity indefinitely without energy loss.

Matching Concept with Options

Review each option: (a) Super conductor, (b) Insulator, (c) Conductor, (d) Semiconductor. Determine which corresponds to the zero-resistance property at absolute zero (0 K).

Selecting the Correct Option

Super conductors are known for showing zero electrical resistance at or close to certain low temperatures, including 0 K. Hence, the correct answer is option (a) Super conductor.

Key concepts

Zero Resistance

Zero resistance is a fascinating phenomenon in the world of physics where an electric current can pass through a material without losing any energy. Normally, as an electric current travels through a wire or any other conductor, it encounters resistance. This resistance can cause energy loss, usually in the form of heat, which can lead to inefficiencies.

However, in materials that achieve zero resistance, current flows smoothly and endlessly without any such losses. This characteristic is extremely rare under normal conditions and is a defining feature of some advanced materials that reach a superconductive state.

Absolute Zero

Absolute zero is the lowest possible temperature, defined as 0 Kelvin, or -273.15 degrees Celsius. It represents a point where almost all molecular motion stops since temperature is a measure of the average kinetic energy of particles in a substance.

Achieving absolute zero is more of a theoretical concept because in practice, it is almost impossible to remove all kinetic energy from a material. Nonetheless, scientists get very close to this temperature in laboratory settings to observe interesting behaviors such as superconductivity in materials.

Electrical Conductivity

Electrical conductivity refers to a material's ability to allow the flow of electric current. It's determined by the number of charge carriers and how easily they can move through the material.

Materials like metals are known for high conductivity because their electrons can move freely. On the other hand, insulators have low conductivity because their electrons are not free to move easily. In superconductors, at certain low temperatures, the conductivity becomes infinite, allowing currents to flow perpetually without diminishing energy.

Material Transition

Material transition describes the change that occurs in a substance under specific conditions, which leads it to alter its properties.

For superconductors, this transition occurs at extremely low temperatures (near absolute zero). As the material cools down, it shifts from a normal conductive state to a superconducting state with zero resistance. This transition is marked by the disappearance of electrical resistance and has significant implications in fields like quantum computing and medical imaging.

Superconductivity

Superconductivity is a state of certain materials characterized by zero electrical resistance and the expulsion of magnetic fields, occurring at very low temperatures. This phenomenon was first discovered in mercury by Heike Kamerlingh Onnes in 1911 when he observed that its electrical resistance completely vanished at 4.2 Kelvin.

Superconductors offer immense potential in technological applications, such as highly efficient power transmission, powerful electromagnets, and the development of maglev trains. Their unique ability to carry current without energy loss can revolutionize how we harness and distribute energy.