CBSE Class 10 Answered

Semiconductors are solid materials with special electrical properties that allow for the flow of electricity through the material to be controlled. Conductivity may be either permanently set or changed as needed by a device. All modern electrical devices contain semiconductors. The most important semiconductor materials are silicon, germanium and gallium arsenide. By adding impurities to a semiconductor, through a process called doping, the properties of the material can be altered to be nearly as conductive as metal.

 

Superconductors are metallic materials that are "pure" conductors of electricity at extreme temperatures. That is, at specified temperatures, superconductors produce precisely zero resistance to an electrical current. There are many materials with superconductive properties at certain temperatures. Some common superconductors include tin, aluminum, nitrogen, mercury, lead, zinc, helium, uranium and titanium. The temperature at which superconductor materials demonstrate zero electrical resistance varies between materials. Another important property of superconductors is that, at the specified temperature, a superconductor requires no applied voltage to maintain its current for an indefinite period.