If ideal things like ideal gas or ideal machine dont exist, then why do we define such things and compare usual things to ideal ones?

Brijesh Kumar You are right. They should be called “simple” things. In reality, they are simplifications of real world systems. So, we should call: “simple gas” and “simple machine”. We use those to make our analysis easier. They are good approximations or starting points of real world systems. So, to call them an “ideal gas” … Read more

If ideal things like ideal gas or ideal machine dont exist, then why do we define such things and compare usual things to ideal ones?

Brijesh Kumar You are right. They should be called “simple” things. In reality, they are simplifications of real world systems. So, we should call: “simple gas” and “simple machine”. We use those to make our analysis easier. They are good approximations or starting points of real world systems. So, to call them an “ideal gas” … Read more

Does the conductance of a semiconducter change when the Fermi level [math]E_F[/math] stays the same, but the distance to the valence band increases?

Brijesh Kumar Conductance depends on the size of the material, so let us talk about conductivity which is independent of physical size. conductivity = [math]ne\mu_n+pe\mu_p[/math] Now, to solve this question, let us make some assumption: The density of states is the same in both materials (Nc, Nv) The mobility for both electrons and holes is … Read more

Does the conductance of a semiconducter change when the Fermi level [math]E_F[/math] stays the same, but the distance to the valence band increases?

Brijesh Kumar Conductance depends on the size of the material, so let us talk about conductivity which is independent of physical size. conductivity = [math]ne\mu_n+pe\mu_p[/math] Now, to solve this question, let us make some assumption: The density of states is the same in both materials (Nc, Nv) The mobility for both electrons and holes is … Read more