Question

Superconductors are substances which:
A. Conduct electricity at low temperature
B. Offer high resistance to the flow of current
C. Offer no resistance to the flow of electricity
D. Conduct electricity at high temperatures

Answer 1

Hint: Make use of the definition of superconductors which says superconductors are conductors which offer very low resistances to the flow of electricity.

Complete step by step solution:
A semiconductor material has an electrical conductivity value falling between that of conductor, such as metallic copper and an insulator such as glass. When two different types of doped regions exist in the same crystal structure a semiconductor junction is created. The behaviour of charge carriers, which include electrons, ions and electron holes at these junctions is on the basis of diodes and transistors. Some common examples of semiconductors are silicon, germanium, gallium, arsenic etc and all the other elements which exist near the “metalloid staircase” on the periodic table.
Thus, superconductors are substances which offer no resistance to the flow of current.
Therefore, the correct answer is option: C

Additional information:
The conductivity of semiconductors can be easily changed or modified by introducing impurities into their respective crystal lattices. This process of adding controlled impurities to a semiconductor is known as doping. The amount of impurity added to an intrinsic (pure) semiconductor varies its level of conductivity. After doping these semiconductors are referred to as extrinsic. By adding these types of impurities to pure semiconductors, the electrical conductivities of these elements are varied by large amounts.

Note: Before being able to solve the question students need to be able to understand the meaning of the terms superconductors, conductors, flow of electrons etc.