Question

What is the difference between thermodynamic pressure and dynamic pressure in transport phenomena?

Answer 1

Dynamic resistance of the diode is the resistance for an AC source deppending of the DC polarization of the diode.The DC polarization determines the dynamic resitance, a high diode DC current is a minimun dynamic resitance because the variation in the curve of diode is more high then less resistance.If the AC source is aproximated5mVpp the diode presents a dynamic resistance of Rd=25.9mV/Idwhere25.9mV is a constant and Id y the DC diode current.The AC source should be small to avoid great changes in Id because:Id(Total)=Id(AC)+Id(DC) [superposition principle]Example:with Id=5mA then Rd=25.9mV/5mA=5.18 OhmsId=0.5mA then Rd=25.9mV/0.5mA=51.8 OhmsThe term Dynamic is because the resistance change arround the working zone of the diode.I hope that the information evacuates yours doubts.