Resistance QER

Explain , in terms of free electrons, why the temperature
and the resistance of a metal wire increase whens the potential
difference across wire is increased.

Before a potential difference is applied free electrons
move rapidly and randomly with no net motion, no
velocity. when a potential difference is applied electrons
accelerate with drift velocity. The temperature increases
as electrons collide with ions in the wire causing heat
to dissipate into thermal energy. Resistance increases due
to collisions between ions and electrons. As D. D increases
more collisions occurs so more energy is lost as heat
increasing temperature. Electrons hit ions harder
when pid is greater increasing vibration of ions.
smaller current for a given p. d. increasing Pd
increases current and drift velocity.