The radius is not enough...You need to know the either the period,the frequency/angular velocity or the tangential velocity...
U can then find B.
Daniel.
#3
R0man
509
0
To calculate the magnetic field intensity and initial velocity of a free electron circling around a radius of 100 nm, we can use the equation for the centripetal force:
F = mv^2/r
Where:
F = Centripetal force (N)
m = Mass of the electron (kg)
v = Velocity of the electron (m/s)
r = Radius of the circular path (m)
We can rearrange this equation to solve for the velocity of the electron:
v = √(Fr/m)
Now, we need to find the centripetal force acting on the electron. This is provided by the magnetic force, which is given by the equation:
Fm = qvB
Where:
Fm = Magnetic force (N)
q = Charge of the electron (C)
v = Velocity of the electron (m/s)
B = Magnetic field intensity (T)
We can substitute the expression for Fm into the equation for the centripetal force:
F = (qvB)v
Simplifying:
F = qv^2B
Now, we can substitute this expression for F into the equation we derived for the velocity of the electron:
v = √((qv^2B)r/m)
Simplifying:
v = √(qBr^2/m)
To find the initial velocity of the electron, we need to know the charge and mass of the electron, as well as the magnetic field intensity. We can find the charge and mass of the electron from a standard reference table, and the magnetic field intensity can be obtained through experimental data or a calculation based on the current and distance from a magnetic source.
Once we have these values, we can plug them into the equation to find the initial velocity of the electron. This will give us the velocity at which the electron needs to move in order to maintain a circular path with a radius of 100 nm.
In summary, to derive the magnetic field intensity and initial velocity for a free electron to circle around a radius of 100 nm, we need to use the equations for centripetal force and magnetic force, and rearrange them to solve for the velocity of the electron. We also need to know the charge and mass of the electron, as well as the magnetic field intensity.
Insights auto threads is broken atm, so I'm manually creating these for new Insight articles.
Towards the end of the first lecture for the Qiskit Global Summer School 2025, Foundations of Quantum Mechanics, Olivia Lanes (Global Lead, Content and Education IBM) stated...
Source: https://www.physicsforums.com/insights/quantum-entanglement-is-a-kinematic-fact-not-a-dynamical-effect/
by @RUTA
If we release an electron around a positively charged sphere, the initial state of electron is a linear combination of Hydrogen-like states. According to quantum mechanics, evolution of time would not change this initial state because the potential is time independent. However, classically we expect the electron to collide with the sphere. So, it seems that the quantum and classics predict different behaviours!
I don't know why the electrons in atoms are considered in the orbitals while they could be in sates which are superpositions of these orbitals? If electrons are in the superposition of these orbitals their energy expectation value is also constant, and the atom seems to be stable!