What happens to the resistance of a conductor as temperature increases?
Show answer & explanation
Correct answer: B
Explanation
Correct Answer
It increases
Explanation
The resistance of a metallic conductor is directly proportional to its temperature. As the temperature rises, the thermal energy of the atoms within the conductor's lattice structure increases, which causes them to vibrate with greater amplitude. These intensified vibrations significantly increase the number of collisions between the moving free electrons and the vibrating atoms. This heightened frequency of collisions acts as a greater obstruction to the flow of electrons, thereby increasing the electrical resistance.
Key Points
For metallic conductors, resistance increases as temperature increases because the kinetic energy of the lattice ions leads to more frequent scattering of charge carriers. This physical change also results in a decrease in the material's overall electrical conductivity. The relationship between resistance and temperature is fundamentally dictated by the increase in collision frequency between electrons and the metallic lattice ions.
Important Questions and Answers
Question: Does the resistance of semiconductors also increase with temperature?
Answer: No, the resistance of semiconductors decreases as temperature increases because the increased thermal energy promotes more electrons from the valence band to the conduction band, enhancing charge carrier concentration.
Question: What is the standard unit of measurement for electrical resistance?
Answer: The standard unit of electrical resistance is the Ohm, which is denoted by the Greek letter Omega .