Saturday, December 12, 2009

Magnetic Loop Antenna This Is The How Much Thermal Energy Is Produced In The Loop?

How much thermal energy is produced in the loop? - magnetic loop antenna this is the

I'm not sure on how to integrate time into the equations of thermal energy. I was always 6.0755E-7, but that seems wrong.

An antenna loop of 2.00 cm ^ 2 and the resistance to 5.06 μOhms perpendicular to a homogeneous magnetic field of magnitude 20.0 to this value. The scale range is reduced to 2.40 ms zero. How much heat energy is in the circuit by generating the box?

2 comments:

cedrus said...

I hope the following helps, but I'm a bit rusty in the theory.


If a change in the magnetic field induces current in a loop, we work with the Faraday's law, which states

The electromotive force (EMF) = - (change of magnetic flux) / time ()

The magnetic flux of the magnetic field area = x
= (20 x 10 ^ -6) x 2,99 x 10 ^ -4
= 59.8 x 10 ^ -10

EMC = (59.8 x 10 ^ -10) / (2.4 x 10 ^ -3) = 24.92 x 10 ^ -7 V

Power = V ^ 2 / R = (24.92x10 ^ -7) ^ 2 / (5.06x10 ^ -6)
= 122.72 x 10 ^ -8

Energy = Power x Time = 122.72 x 10 ^ -8 x 2.4 x 10-3
= 2.95 x 10 ^ -9

MBenz said...

When the magnetic field drops to zero, the changing magnetic flux induces a current in the loop of wire. It is managed in Faraday law: E = df / dt, where E is the induced emf (in volts), F is the magnetic flux t is the time.

So, first calculate the magnetic flux through the coil, the B * A, where B is the magnetic field and A is the area of the loop. Thus, the flow (Weber 2.00cm ^ 2) * (20x10 ^-6T) = 4x10 ^ -9.

The flow of drops of 4x10 ^ -9 to 0 2.4x10 ^ -3 seconds, so that the induced EMF (4x10 ^ -9) / 2.4x10 ^ -3 = 1.67x10 ^ -6 V.

This leads to an induced voltage = current, which can be calculated with V = I * R I = (1.67x10 ^-6V) / (5.06x10 ^ -6 ohms) 0.33 amps.

The thermal energy produced is exactly equal to the power dissipated by the current and resistance in the loop. The formula for power is P = I * R ^ 2, (5.06x10 ^ -6 ohms) * (0.33 amps) ^ 2 = 5.5x10 ^ 7 watts, which is pretty close to what you already have!

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