Question

The resistivity of metal increases with increase in temperature because:

• A. the speed of the electrons in the metal ions decreases
• B. the average distance between the metal ions increases
• C. the concentration of conduction electrons increases
• D. the concentration of conduction electrons decreases

Answer 1

Answer: (B)

If the metal is heated as a result of heating, the space between atoms increases because of expansion. This increases the time to travel the distance between atoms. During this time the electrons have more collisions with other atoms photon etc. Because of it drift velocity reduces and hence conductivity reduces. Therefore, increases resistivity.