All Questions
Tagged with electromagnetism homework-and-exercises
1,551
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Equations of motion for Lagrangian of scalar QED [closed]
I really would appreciate your help with this exercise.
I have the Lagrangian for scalar electrodynamics given by:
$$\mathcal{L}=-\frac{1}{4}F_{\mu\nu}(x)F^{\mu\nu}(x)+(D_\mu\varphi(x))^*(D^\mu\varphi(...
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1
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Effect of incident angle on wavelength of transmitted wave for normal polarisation?
In my electrodynamcis assignment I'm being asked to derive the wavelength of a normally polarised wave transmitted through a glass/air interface as a function of $n_1$ (the refractive index of the ...
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What does "90 degrees ahead of phase" mean in inductance problems?
I've been working on this homework problem and I have determined that the induced EMF on the right coil is sin(x-90). However, I do not understand what "ahead of phase means." When I graph ...
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No displacement current should be produced in this case, but it does!
Considering this question, i think the concept used is wrong coz direction of E produced due to changing magnetic field is along the circular loop(tangential at each point on loop) of radius r. While ...
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1
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48
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Effects of dielectric on force between charged bodies?
The electrostatic force between the plates of a charged isolated capacitor remains unchanged when dielectric fills whole space between plates.
But when we take 2 isolated point charges in a dielectric ...
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Coilgun projectile force calculation
Please excuse me if I am completely wrong because I am a 9th grader but I hopefully am able to explain briefly about my problem. I was trying to create a function to calculate the Force of an iron ...
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1
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1
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57
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Path of a relativistic charge due to a (nearly) infinitely massive charge [closed]
Suppose we know the position, velocity of a charge at time $t=0$ and its rest mass is also known. It is attracted by a (nearly) infinitely massive known opposite charge which is at rest and always be ...
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Is there a $H$-field formed by a uniformly moved, charged ball?
Imagine a charged ball with surface charges. Let it travel with a constant velocity $v$.
Imagine a point outside the ball. Since the charge is moving, there is a electric displacement displacement ...
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2
answers
578
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Maxwell's equations with differential form formalism
I've been reading Sean Carroll's book on GR and I stumbled upon an exercise on EM using $p$-forms. I think I've solved the problem correctly but I am having problems with my answers. I'll provide the ...
- 147
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3
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225
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Derivation of Maxwell's equations using Lagrangian formalism [duplicate]
Some time ago, I read in Landau's Theoretical Physics Course you could derive Maxwell's equations using the Lagrangian formalism, and I find this to be exciting. Unfortunately, I don't have access to ...
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Field Momentum of a Toroid with a point charge at its center
I´ve been solving the following problem and I need some guidance. The problem asks to calculate all the components of the field momentum of a circular toroidal coil of mean radius a and N turns with a ...
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What is the relationship between the energy absorbed and reemitted by an atom?
What is the relationship between the energy absorbed and emitted by an atom with the model of Lorentz?
In the Lorentz model of an atom, we have that, using the effective cross-sections we might get ...
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Direction of propogation of a EMW [closed]
If let say i have an EMW given by- (Note the difference between $k$ and K)
B(x,y,z)=$B_0sin[(x+y)\frac{K}{√2}+wt]\hat k$
i got confused in 2 different outcomes when i wanted to find out the direction ...
- 367
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39
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Covariant derivative property
I am trying to demonstrate this propertie
$$
\not{D}^2= \mathcal{D}^\mu \mathcal{D}_\mu-\frac{i}{4}\left[\gamma^\mu, \gamma^\nu\right] F_{\mu \nu}
$$
where $\not{}~$ is the Feynmann slash, and $D_\mu ...
- 161
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How can I estimate the force of an electromagnet?
I am doing an experiment on electromagnetism, basically I am just testing the pulling force of an electromagnet using a newton meter with a magnetic hook and seeing how the pulling force changes as i ...
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