Many of the analysis procedures assume radial symmetry, which leads to a symmetric antenna pattern. In practice, symmetry is often, but not always the case. For example, the antenna pattern will be dependent on the geometry and polarization of the antenna feed. In the case of linearly...
E-M fields carry both energy and momentum. The momentum density field points in the same direction as the Poynting vector (E cross H), and there can be angular momentum in the fields as well.
David Griffiths has some great examples in his Intro to Electrodynamics if you have access to that.
Far enough away, most magnets can be approximated as a magnetic dipole moment m, which is a vector. For a magnetic dipole m at the origin and oriented in the z-direction, you get
\vec{B} = {\mu_o m \over {4\pi r^3}} (2\cos\theta \hat{r} + \sin\theta\hat{\theta})
The trick for your...
Remember, you are multiplying the e^{-j \omega} by a chain of delta functions (in \omega-space). The only thing that matters is where the delta function is nonzero.
Remember f(x)\delta(x-a) = f(a)\delta(x-a)
Don't confuse "suppressed carrier" with a spectrum that has no power spectral density at your carrier frequency.
Technically speaking, a non suppressed carrier will have a "delta function" at the carrier frequency. Practically, what this will mean in the lab is that your power reading on...
Not sure if this helps much, but the form of your solution is very similar to the fields around a wire of radius r parallel to a ground plane a distance d away. If the potential separating the wire and the plane is V, you get that the E-field at the wire is approximately:
E = V/(r*ln(2d/r))...
Many CPUs on higher-end computers use heat sinks with heat pipes, which are based on evaporative cooling. Having said this, I don't think the CPU surface gets much below 50C.
Typically, you see:
Pr (dBW) = EIRP (dBW) + Gr (dB) - FSL (dB)
where Gr is the antenna gain of your receive antenna, FSL is as you calculated in the equation, and EIRP is the effective isotropic radiated power and is given by
EIRP (dBW) = Pt (dBW) + Gt (dB),
where Pt is the...
Using ferrites as asborbers in microwave and RF systems is often done, but a bit of a black art. You have to experiment with the material, location, and size a bit. I would suggest using a sheet of ferrite-loaded rubber. These sheets come loaded with various ferrites and they come in various...
Apply the usual rules for ideal op amps. That is, the voltage between the inverting and noninverting terminals is zero and the current flowing into these terminals is zero.
It may then be helpful to write the output voltage as a function of the source current. A loop equation will relate...
This is a classic. Forgive me if this has been posted before.
You have 12 coins, and you know that one one of the coins may be fake. You also know that a fake coin will not have the same weight as a good coin: it will either be heavier or lighter. You have at your disposal a balance scale...
You can keep dividing the set in half, maybe making a rule that in the case of an odd numbered set the extra bottle goes in the first half. Each taster is then assigned to taste all the bottles in the first half of each subgroup.
That is, taster 1 tastes the first N/2 bottles. Taster 2 tastes...