Finding the gyromagnetic ratio of an axially symmetric body

In summary, the conversation discusses the relationship between angular momentum, magnetic dipole moment, and the mass and charge of an axially symmetric body. The relationship is expressed as m = g L, where L is the angular momentum, g is the desired ratio, and m is the magnetic dipole moment. The moment of inertia can also be written as I_\omega=\int \rho_m d^2 d\tau, where d is the distance from the axis of symmetry. The conversation then delves into the calculation of g and the role of current and speed in the equation.
  • #1
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Homework Statement



So, we can presumably write that m = g L, where L is the angular momentum, g the ratio wanted, and m magnetic dipole moment of an axially symmetric body. Total mass is M, total charge Q, mass density [itex]\rho_m(r)=\frac{M}{Q}\rho_e(r)[/itex], where [itex]\rho_e(r)[/itex] is charge density.

Homework Equations



Moment of inertia can also be written [itex]I_\omega=\int \rho_m d^2 d\tau[/itex] where d is the distance from the axis of symmetry.

The Attempt at a Solution



I guess the dipole moment is in the direction of the axis of the symmetry, as is the angular velocity and it can be written:
m = g I[itex]_\omega [/itex] ω

RHS:
= g ω [itex]\hat{z}[/itex] I[itex]_\omega [/itex]

LHS:
m = I [itex] \int d\vec{a} [/itex]

Here is where I guess I'm having conceptual problems. I is the total current, part of which should be a current flowing through a differential circular loop inside the body, at distance d, that is to say:

I = [itex]\int \left| v \right| \rho_e d\tau [/itex] , where [itex]\left|v\right|[/itex] is the module of radial speed of a differential volume element (at distance d) that can be written: [itex]\left|v\right|=\left|\omega\right|\left|r\right|[/itex]sin[itex]\theta [/itex]= ωd. [itex] \int d\vec{a} [/itex] of a differential loop in question is simply [itex] d^2 \pi[/itex]. So, I am getting:

g ω [itex]\int \rho_m d^2 d\tau[/itex] =ω [itex]\int d^3 \pi \frac{M}{Q} \rho_m d\tau [/itex]

Where did I go wrong, how to find g?
 
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  • #2
anyone? :( the integrals are supposed to annihilate each other leaving me with a factor ~M/Q
 

FAQ: Finding the gyromagnetic ratio of an axially symmetric body

1. What is the gyromagnetic ratio?

The gyromagnetic ratio, also known as the magnetogyric ratio, is a physical constant that relates the magnetic moment of a particle to its angular momentum. It is often denoted by the symbol γ and has units of radian per second per tesla (rad s⁻¹ T⁻¹).

2. What is an axially symmetric body?

An axially symmetric body is a three-dimensional object that has a rotational symmetry around an axis. This means that if the object is rotated around its axis, it will appear the same from any angle. Examples of axially symmetric bodies include cylinders, spheres, and cones.

3. How is the gyromagnetic ratio calculated?

The gyromagnetic ratio can be calculated by dividing the magnetic moment of a particle by its angular momentum. It can also be derived from other physical constants, such as the charge and mass of the particle, through theoretical models and experiments.

4. Why is finding the gyromagnetic ratio important?

Knowing the gyromagnetic ratio of a particle or object is important in understanding its behavior in a magnetic field. It is also a fundamental constant in many areas of physics, including quantum mechanics, nuclear magnetic resonance, and electron spin resonance.

5. How is the gyromagnetic ratio of an axially symmetric body measured?

The gyromagnetic ratio of an axially symmetric body can be measured using various experimental techniques. One common method is by observing the precession of the object in a magnetic field. The gyromagnetic ratio can also be calculated from the resonant frequency of the object in a magnetic field, or from the frequency shift of an electromagnetic wave passing through the object in a magnetic field.

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