The oscillating magnetic field in a plane EM waves is given by By=8x10to the power of 6sin[2x10to the power of 11 t+300pie x]T.Calculate wavelength of EM wave and also write an expression for oscillatin electric field?
Asked by SUHAS MELMURI | 14th Nov, 2013, 05:38: AM
Expert Answer:
Given that,
B = 8×106 sin(2×1011 t + 300∏X ) T .....................(1)
Now the standard equestion of magnetic field is always written in the form of
B = Bo sin(kx ± ωt ) T ...........................(2)
Where, Bo = amplitude of EM wave
k = wave vector
ω = frequency of osscilation
By comparing eq (1) with (2),
k = 300∏
The wave vector is given by,
k = 2∏/λ
λ = 2∏/k
= 2∏/300∏
= 0.0066 m
= 6.6 × 10-3 m
In a plane EM wave direction of magnetic field, electric field and direction of propagation are always mutualy perpendicular to each other.
Therefore, from eq (1) the electric field is in Z - direction.
The relation between electric and magnetic field is given by,
Hence,
E = Eo sin(kx ± ωt )
Ez =(8×106 )× (3×108) sin(2×1011 t + 300∏X ) ..........(3)
Equestion (3) gives the expression for electric field.
Given that,
B = 8×106 sin(2×1011 t + 300∏X ) T .....................(1)
Now the standard equestion of magnetic field is always written in the form of
B = Bo sin(kx ± ωt ) T ...........................(2)
Where, Bo = amplitude of EM wave
k = wave vector
ω = frequency of osscilation
By comparing eq (1) with (2),
k = 300∏
The wave vector is given by,
k = 2∏/λ
λ = 2∏/k
= 2∏/300∏
= 0.0066 m
= 6.6 × 10-3 m
In a plane EM wave direction of magnetic field, electric field and direction of propagation are always mutualy perpendicular to each other.
Therefore, from eq (1) the electric field is in Z - direction.
The relation between electric and magnetic field is given by,

Answered by Komal Parmar | 18th Nov, 2013, 04:41: PM
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