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physics noob
Jul24-05, 09:18 PM
hi guys i had a quick question about EM waves

given EM travelling west, B field oscilates vertically and has f= 80,000 Hz and a rms strength of 6.75e-9 T what are the frequency and rms strength of electric field and what direction...


so for direction i have it ocscillating horizontally and for rms strength i have E= cB

so E = 2 v/m but for frequency i have no idea


wavelength * f = v but i have no idea what wavelength is.... any help is appreciated thanks!

geosonel
Jul24-05, 10:54 PM
hi guys i had a quick question about EM waves

given EM travelling west, B field oscilates vertically and has f= 80,000 Hz and a rms strength of 6.75e-9 T what are the frequency and rms strength of electric field and what direction...


so for direction i have it ocscillating horizontally and for rms strength i have E= cB

so E = 2 v/m but for frequency i have no idea


wavelength * f = v but i have no idea what wavelength is.... any help is appreciated thanks!
you correctly solved the first questions
you're very close to the "frequency" answer.
how is the freq of the E field related to the freq of the B field in this EM wave?
(hint: think "equal")

also FYI:
(frequency)*(wavelength) = velocity = c = 3x108 m/sec
since you know that frequency = 80,000 Hz, you can also determine wavelength of this EM wave (altho it's not required for the problem solution)

physics noob
Jul25-05, 11:06 AM
thanks for your help, i got it now, forgot that c=V thanks again

physics noob
Jul25-05, 11:12 AM
actually, im kinda stuck again,,,,, if i used V=c,,, then i would get a wavelength of 3750m, and then when i try to find frequency of E field, i would get that it has the same frequency of B field, becuase A=B B=C
A must = C
A being B field frequency and C being E field frequency

OlderDan
Jul25-05, 11:52 AM
when i try to find frequency of E field, i would get that it has the same frequency of B field
Why does this trouble you? Why would they not have the same frequency?

http://hyperphysics.phy-astr.gsu.edu/hbase/waves/emwavecon.html

physics noob
Jul25-05, 11:56 AM
...i GUESS i can live with it...lol...............thanks guys