## GRE Physics GR 1777, Problem 031 Solution

GRE Physics GR 1777 Problem Solution 031. Optics and Wave Phenomena (Standing waves) You should know about Standing wave in a pipe  The frequency of the open at both ends where n is the harmony, v is the speed of sound, L is the length of the pipe.  The frequency of only one fixed end Note that for…

## GRE Physics GR 1777, Problem 030 Solution

GRE Physics GR 1777 Problem Solution 030. Optics and Wave Phenomena (Doppler effect) You should know about Doppler effect The observed frequency is given by where : emitted frequency  : propagation speed of waves in the medium : speed of the receiver relative to the medium, added if the receiver is moving towards the source, subtracted if…

## GRE Physics GR 1777, Problem 029 Solution

GRE Physics GR 1777 Problem Solution 029. Thermodynamics (Thermodynamics processes) You should know about Thermodynamics processes Adiabatic process (No heat transfer) Isobaric process (Constant pressure) Isothermal process (Constant temperature) When they are starting from the same state, the work done by an isothermal process is always bigger than the work done by an adiabatic process. Solution Answer…

## GRE Physics GR 1777, Problem 028 Solution

GRE Physics GR 1777 Problem Solution 028. Thermodynamics (Work) You should know about in Thermodynamics Solution Answer (C) 40 J

## GRE Physics GR 1777, Problem 027 Solution

GRE Physics GR 1777 Problem Solution 027. Electrodynamics (Electromagnetic radiation) You should know about Gamma decay: An excited radioactive nucleus decays to a lower energy state by emitting a gamma-ray photon. Solution Answer (A) gamma rays

## GRE Physics GR 1777, Problem 026 Solution

GRE Physics GR 1777 Problem Solution 026. Quantum Mechanics You should know about Heisenberg’s Uncertainty Principle Solution Answer (E) Reference https://en.wikipedia.org/wiki/Uncertainty_principle

## GRE Physics GR 1777, Problem 025 Solution

GRE Physics GR 1777 Problem Solution 025. Quantum Mechanics (Hermitian operator) You should know about The hermitian operator’s eigenvalues are real. Solution Answer (B) 1, -1

## GRE Physics GR 1777, Problem 024 Solution

GRE Physics GR 1777 Problem Solution 024. Quantum Mechanic (Quantum number) You should know about Quantum number (Principal quantum number, spin quantum number) Hund’s first rule Solution Answer (C) Reference https://en.wikipedia.org/wiki/Quantum_number

## GRE Physics GR 1777, Problem 023 Solution

GRE Physics GR 1777 Problem Solution 023. Quantum Mechanics (Positronium) You should know about Rydberg constant for positronium may be calculated from the reduced mass Solution Answer (B) 0.5 Reference https://en.wikipedia.org/wiki/Positronium https://en.wikipedia.org/wiki/Rydberg_constant

## GRE Physics GR 1777, Problem 022 Solution

GRE Physics GR 1777 Problem Solution 022. Quantum Mechanics (Bohr model) You should know about The energy of the n-th level for any atom: Solution Answer (A) decreased by a factor of 9 Reference https://en.wikipedia.org/wiki/Bohr_model