Gitofa Shah PHYSICS   -   Statistical Mechanics

A system undergoes a reversible adiabatic process. What is the change in entropy of the system?

In a reversible adiabatic process, the entropy of the system remains constant, ΔS = 0.
Gitofa Shah PHYSICS   -   Statistical Mechanics

What is the name of the theorem that relates the entropy of a system to the number of possible microstates?

Boltzmann's theorem states that the entropy of a system is proportional to the logarithm of the number of possible microstates, S = k * ln(Ω).
Gitofa Shah PHYSICS   -   Statistical Mechanics

A system is in thermal equilibrium with a reservoir at temperature T. What is the probability of finding the system in a microstate with energy E?

The probability of finding a system in a microstate with energy E is given by the Boltzmann distribution, which is proportional to e^(−E/kT) and normalized by the partition function Z(T).
Gitofa Shah PHYSICS   -   Statistical Mechanics

What is the name of the statistical ensemble that describes a system with a fixed number of particles, volume, and energy?

The microcanonical ensemble describes a closed system with a fixed number of particles (N), volume (V), and energy (E), and is characterized by a fixed energy and particle number.
Gitofa Shah PHYSICS   -   Quantum Mechanics

What is the name of the process by which a particle and its antiparticle annihilate into photons?

Pair annihilation is the process by which a particle and its antiparticle (such as an electron and a positron) annihilate into photons, releasing energy in the form of radiation.
Gitofa Shah PHYSICS   -   Quantum Mechanics

A beam of particles passes through a Stern-Gerlach apparatus with a magnetic field gradient oriented in the z-direction. What is the effect on the beam?

The Stern-Gerlach apparatus splits the beam into two components with opposite spin components in the direction of the magnetic field gradient, which is the z-direction in this case.
Gitofa Shah PHYSICS   -   Quantum Mechanics

What is the purpose of the wave function renormalization in Quantum Field Theory?

Wave function renormalization is a process in Quantum Field Theory that removes the infinite self-energy of particles, making the theory finite and well-defined.
Gitofa Shah PHYSICS   -   Quantum Mechanics

A particle is in a superposition of two energy eigenstates, |ψ= a|E1+ b|E2. What is the probability of finding the particle in the energy eigenstate |E1?

The probability of finding the particle in the energy eigenstate |E1is given by the square of the amplitude of the coefficient of |E1, which is |a|^2 / (|a|^2 + |b|^2).
Gitofa Shah PHYSICS   -   Quantum Mechanics

What is the physical significance of the commutator of the position and momentum operators in Quantum Mechanics?

The commutator of the position and momentum operators, [x, p] = iℏ, is a fundamental concept in Quantum Mechanics. It represents the uncertainty principle, which states that certain pairs of physical properties (such as position and momentum) cannot be precisely known at the same time.
Gitofa Shah PHYSICS   -   Quantum Mechanics

In the context of quantum mechanics, what does the term "wavefunction collapse" refer to?

Wavefunction collapse refers to the process where a wavefunction, which initially exists in a superposition of multiple eigenstates, abruptly transitions into a single eigenstate as a result of a measurement. This concept is central to the Copenhagen interpretation of quantum mechanics, which posits that the act of measurement causes the system to 'choose' one of the possible outcomes, collapsing the wavefunction to a specific state.

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