GRE Physics GR 1777 Problem Solution 006. Electromagnetism (Electromagnetic Waves) The problem asks you to determine The direction of the magnetic field of a plane electromagnetic wave. The problem gives The electric field. It is given by You should know about Property of the electromagnetic waves: The oscillations of electric and magnetic fields are perpendicular…

# Category: GRE Physics

## GRE Physics GR 1777, Problem 021 Solution

GRE Physics GR 1777 Problem Solution 021. Electrodynamics (Cyclotron) Solution The cyclotron frequency is the frequency of a charged particle moving perpendicular to the direction of a constant magnetic field B. Since the motion of a charged particle in the cyclotron is circular (because of a uniform magnetic field), we can calculate the cyclotron frequency…

## GRE Physics GR 1777, Problem 020 Solution

GRE Physics GR 1777 Problem Solution 020. Electrodynamics (Magnetic field) Solution The magnitude of the magnetic field can be obtained from the Biot-Savart law. where is the radius of the loop and is the current. In this problem, the radius of the circular loop is , the magnitude of the magnetic field at the center…

## GRE Physics GR 1777, Problem 019 Solution

GRE Physics GR 1777 Problem Solution 019. Classical Mechanics (Work-Energy Principle) Solution From the work-energy theorem, Since the work done by the box is and the change of the kinetic energy is Therefore, The force is Answer (C) 3N Reference https://en.wikipedia.org/wiki/Work_(physics)#Work–energy_principle

## GRE Physics GR 1777, Problem 018 Solution

GRE Physics GR 1777 Problem Solution 018. Classical Mechanics (Angular Momentum) Solution Angular momentum in a circular motion is where is angular momentum, is the mass of the satellite, is the velocity, and is the orbital radius. In this problem, two satellites are identical. So the mass of the satellite is equal. The orbital radius…

## GRE GR 1777, Problem 017 Solution

GRE Physics GR 1777 Problem Solution 017. Classical Mechanics (Stellar Dynamics) Solution In Keplar’s Thrid law, the square of the orbital period of a planet is proportional to the cube of the semi-major axis of its orbit. where is the orbital period, and is the semi-major axis of the planet. For system 1 the radius…

## GRE Physics GR 1777, Problem 016 Solution

GRE Physics GR 1777 Problem Solution 016. Optics (Electromagnetics) This problem asks for the application of Fermat’s principle of ray optics to other optics laws. Solution This principle shows the path of the light, so it can also be used to explain reflection and refraction of the light. So we can derive Snell’s law and…

## GRE GR 1777, Problem 014 Solution

GRE Physics GR 1777 Problem Solution 014. Quantum Mechanics (Planck length), Dimensional Analysis Solution If you don’t know the Planck length, that’s fine. This question asks that you know about the dimensional analysis. The unit of the length should be . To find the proper expression for length, we construct the equation like this: The…

## GRE Physics GR 1777, Problem 013 Solution

GRE Physics GR 1777 Problem Solution 013. Quantum Mechanics (Infinity potential wall) Solution Infinity potential wall problem is one of the basic problems in quantum mechanics. So I recommend you to remember some equation about it. The energy eigenvalues of a particle of mass inside a one-dimensional box are . And the boundary condition ()…

## GRE Physics GR 1777, Problem 012 Solution

GRE Physics GR 1777 Problem Solution 012. Quantum Mechanics (Quantum number) The magnetic quantum number can be determined as Thus, the number of allowed values of is . Therefore, when , the number of allowed values of is 5. Answer (E) References https://chem.libretexts.org/Core/Physical_and_Theoretical_Chemistry/Quantum_Mechanics/10%3A_Multi-electron_Atoms/Quantum_Numbers https://en.wikipedia.org/wiki/Magnetic_quantum_number