## What is meant by degeneracy pressure?

[ dĭ-jĕn′ər-ə-sē ] A pressure exerted by dense material consisting of fermions (such as electrons in a white dwarf star). This pressure is explained in terms of the Pauli exclusion principle, which requires that no two fermions be in the same quantum state.

## What force causes degeneracy pressure?

Due to Pauli exclusion principle, electrons cannot occupy the same quantum state simultaneously, even if you try to do so (by making them degenerate). That’s why they generate a pressure under strongly degenerate conditions.

**What does degeneracy pressure depend on?**

The key feature is that this degeneracy pressure does not depend on the temperature but only on the density of the fermions. Degeneracy pressure keeps dense stars in equilibrium, independent of the thermal structure of the star.

**How is degeneracy pressure overcome?**

In the core, the force of gravity is sufficient to overcome the electron degeneracy pressure, and the electrons are driven into the atomic nuclei. Each electron combines with a proton, producing a massive sphere of neutrons.

### Is electron degeneracy pressure a force?

A2A: Electron degeneracy pressure is just the confined momentum of a concentration of fermions, who because of the exclusion principle have to stack up into higher momentum states rather than herding together into a low momentum state. But the exclusion principle isn’t a force, it is more like a mathematical identity.

### Does degeneracy pressure vary with temperature?

It does not depend on temperature! Equate this central pressure with that which can be provided by an electron gas and substitute for the density: This expression for the radius illustrates the interesting property that an object supported by an electron gas is smaller if it is more massive.

**Is degeneracy pressure a consequence of quantum mechanics?**

Degeneracy pressure isn’t a new force, rather it is just a consequence of the fermi-statistics of half-integer spin particles. As for fermi-statistics itself, it is a consequence of the basic properties of quantum field theory, but that would be too much to get into at the moment.

**What is degeneracy pressure and how is it important to the existence of white dwarfs and neutron stars?**

Degeneracy pressure is a kind of pressure that arises when subatomic particles are packed as closely as the laws of quantum mechanics allow. Degeneracy pressure is important to neutron stars and white dwarfs because it is what allows them to resist the pull of gravity.

## What happens when electron degeneracy pressure is overcome?

If electron degeneracy pressure is overcome by gravity the object collapses and the electrons are expelled and the nuclei merge. The protons get converted into neutrons. This collapse can only happen in very massive objects.

## What is the difference between electron degeneracy pressure and neutron degeneracy pressure?

Electron degeneracy pressure is due to the tightly packed electrons, but neutron degeneracy pressure is due to tightly packed neutrons.

**What happens to degeneracy pressure if you raise the temperature of a gas?**

One important consequence is that the pressure of degenerate matter does not depend on temperature any more as is the case for normal matter when increasing its temperature causes a gas to also increase its pressure (see ideal gas law).

**Is electron degeneracy pressure stronger than neutron degeneracy pressure?**

If the pressure keeps building up, the electrons are forced to combine itself with protons forming neutrons. They also have their degeneracy pressure which is way much higher than the electron degeneracy pressure.

### What happens to degenerate energy levels during Zeeman effect?

Due to Zeeman effect, some degenerate energy levels will split into several non- degenerate energy levels with different energies. This allows for new transitions which can be observed as new spectral lines in the atomic spectrum.

### How do Zeeman shifts affect frequency?

The effect of the Zeeman shifts can be seen experimentally. If a particular transition in the absence of an applied field produces radiation at frequency ‘ 0, then the frequency in the presence of a field will be given by h’ = h’ 0+ µ Bg(JLS) M JH – µ Bg(J’L’S’) M

**What is Zeeman effect in neon and Mercury?**

In this experiment we will study Zeeman effect in neon and mercury for which the theory of Zeeman effect is somewhat more tractable. Non-relativistic quantum theory accounts for only one type of angular momentum called orbital angular momentum. The Hamiltonian for an electron with angular momentum l

**What is the Zeeman shift in first order perturbation?**

First order perturbation theory tells us that energy levels are shifted by “E = µ BMlH [1] where Mlis the quantum number for the component of l along the field. If an atom had only a single electron and the electron had only “orbital” angular momentum, then Eq. 1 would represent the Zeeman shift.