Total Power Radiated by Isotropic Source: 1.885mV

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VThis conversation is discussing the calculation of total power radiated by an isotropic source in free space at a distance of 10km. The relevant equation is Prad(theta,phi,r) = (1/2)*eta*|E|^2. After plugging in the given values, the total power is calculated to be 1.885mV. However, to accurately calculate the total power, integration of the entire surface of radius 10km is needed. The final result is 0.528*pi*mV. In summary, the total power radiated by the isotropic source is 0.528*pi*mV.
  • #1
PassThePi
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What is the total power radiated by an isotropic source in free space is |E| = 1mV/m at a distance of 10km?

Relevant Eqns:
Prad(theta,phi,r) = (1/2)*eta*|E|^2

Prad(theta,phi,r) = (1/2)*377*0.001^2*(10000) = 1.885mV

Is this correct? I feel like it can't be that simple.
 
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  • #2
Your 1mV/m is measured at a point 10Km away, to calculate the total power of the isotropic source( E is equal in magnitude at any point on the sphere), you need to have some sort of integration of the whole surface of radius of 10Km.

I don't understand your formula at all!
 
Last edited:
  • #3
Oh I think I see...

Prad(theta,phi,r) = (1/2)*eta*|E|^2

Prad(theta,phi,r) = (1/2)*377*0.001^2*(10000) = 1.885mV

PradTotal = (int(0|2*pi))(int(0|pi))(Prad(theta,phi,r)*r2sin(theta)dtheta*dphi

PradTotal = 2*pi*0.132*(-cos(\0|pi)) = 0.528*pi
 

1. What is the meaning of "Total Power Radiated by Isotropic Source: 1.885mV"?

The term "Total Power Radiated by Isotropic Source" refers to the total amount of electromagnetic energy emitted by a source that radiates equally in all directions. The measurement of 1.885mV represents the strength or intensity of this radiation.

2. How is the total power radiated by an isotropic source calculated?

The total power radiated by an isotropic source is calculated by multiplying the power density (in watts per meter squared) by the surface area of a sphere with a radius equal to the distance from the source. This calculation assumes that the radiation is evenly distributed in all directions.

3. Is the total power radiated by an isotropic source constant at all distances?

No, the total power radiated by an isotropic source decreases as the distance from the source increases. This is due to the inverse square law, which states that the intensity of radiation is inversely proportional to the square of the distance from the source.

4. What is an isotropic source and how does it differ from other sources?

An isotropic source is one that radiates energy equally in all directions, with no preferential direction. This differs from other sources, such as directional antennas, which have a specific direction of radiation. Isotropic sources are often used as a theoretical reference for comparison with actual sources.

5. How is the total power radiated by an isotropic source related to other measures of radiation, such as electromagnetic fields?

The total power radiated by an isotropic source is related to other measures of radiation, such as electromagnetic fields, through the power density. The power density is the amount of power per unit area and is related to the strength of the electromagnetic field. As the total power radiated by an isotropic source increases, so does the power density and the strength of the electromagnetic field.

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