With an increase in temperature, the number of phonons increases. So the phonon induced scattering also increases, thus decreasing the mean free path. So resistivity increases. This is in the case of metals. For semiconductors the scenario is different.
As per classical statistics, with increasing temperature, the velocity of the particle (here electron) increases. Also with an increase in velocity, scattering due to lattice (phonons) also increases, thus causing a reduction of mean free time.
@@DeepakKumar-yo7xd *velocity is independent* it is the conclusion of sommerfeld model which will be discuss in next lecture. According to drude model velocity is temperature dependent.
@@vasudevanm.v2760 at 21:50 see He *decrease temperature* and resistivity so Scattering time tau increase. Now but velocity v ∝ √ T But he increasing velocity. That is my question. In same condition taking different outcomes
Bro has any of your friend got selected in BARC ?, If you know someone who also has given BARC interview , please make a discussion video with them as well ?
thanks
great lecture
How is the resistivity dependent on temperature?
With an increase in temperature, the number of phonons increases. So the phonon induced scattering also increases, thus decreasing the mean free path. So resistivity increases. This is in the case of metals. For semiconductors the scenario is different.
@@vasudevanm.v2760 Say Simply more collisions due to increase in entropy(randomness) of electrons
In case of velocity you are increasing temperature. But to get tau you are decreasing temperature..🤔🤔🤔.
Why?
As per classical statistics, with increasing temperature, the velocity of the particle (here electron) increases. Also with an increase in velocity, scattering due to lattice (phonons) also increases, thus causing a reduction of mean free time.
bro, velocity is independent of temperature. Only scattering time depends on temperature in the way explained. Where is the confusion!
@@DeepakKumar-yo7xd *velocity is independent* it is the conclusion of sommerfeld model which will be discuss in next lecture.
According to drude model velocity is temperature dependent.
@@vasudevanm.v2760 at 21:50 see
He *decrease temperature* and resistivity
so Scattering time tau increase.
Now but velocity v ∝ √ T
But he increasing velocity.
That is my question.
In same condition taking different outcomes
@@spfi3881 yeah, you are right actually.
Thanks sir
Bro has any of your friend got selected in BARC ?, If you know someone who also has given BARC interview , please make a discussion video with them as well ?
As there is only one physics BARC interview video , which is yours. Thanks for that