Hi.

In the formula E = V B L for the "Conclusions" paragraph at near bottom of page

----> http://cfpub.epa.gov/ncer_abstracts/index.cfm/fuseaction/display.abstractDetail/abstract/8630/report/F

 

B being 0.00004 Tesla,

V being 2 metres/second,

L being 300 metres;

 

Should the V,L units be in centimetres or metres for E to be Volts ?

 

[ Did not copy and paste the pertinent portion here because figure 4 shows 'Copyright' ]

 

 

V is in metres per second

L is in metres

E is in volts

B is in Tesla or webers per square metre

 

Then everything is in rationalised MKS units (ISO metric).

 

Note also that your formula uses the vector cross product VxB, since both B and V are vectors.

This would normally also have a cosine of the angle between them, but since this is 90 cos(90) = 1.

Edited October 12, 201411 yr by studiot

Thanks again, studiot.

 

Solving with metres, the voltage that the strait of Gibraltar tidal current could produce on MHD with the earth magnetic field, is 24 millivolts. A surprisingly low figure.

Solving with centimetres, is 240 Volts.

 

Magnetic field N <---> S; current E <---> W

Millivolts sounds right.

 

Think of a solar panel or Hall effect generator.or even a humble accumulator.

 

They achieve higher voltages by series connection od multiple unts.