Superconductors are substances which

Question

Question

This question was previously asked in

WBCS Prelims 2020 Official Paper

Answer 1

The correct answer is offer no resistance to the flow of current.

Key Points

Superconductors are substances that have zero resistance at a very low temperature. so electricity flows through them rapidly.
eg- Mercury below 4.2 K, Lead below 7.25 K acts like superconductors. (K= kelvin)

Additional Information

Current flows in the opposite direction in which direction free electrons of a substance flow. This phenomenon is known as current electricity.
A substance can be divided into four types based on the conductivity of the electricity or you can say based on the free electron number present on their surface:
- Insulators: The substances that do not allow the current to flow through them. They don't have any free electrons.
  - eg- Cotton, Wood, Glass, etc.
- Conductors: The substances that allow the current to flow through them are known as conductors. They have a large number of free electrons.
  - eg- Copper, Silver, Iron, Aluminium, etc.
- Superconductors: This substance has zero resistance at a very low temperature. so electricity flows through them rapidly.
  - eg- Mercury below 4.2 K, and Lead below 7.25 K act like superconductors. (K= kelvin)
- Semiconductors: Some substances that have electrical resistivity between those of conductors and insulators.
  - eg- Silicon and germanium.