Question

The magnetic field in a plane electromagnetic wave is given by: by= 12 x 10. The magnetic field in a plane electromagnetic wave is given by: by= 12 x 10-8 sin (1.20 x 107 z + 3.60 x 10 15 t ) t. Calculate the (i)wavelength and frequency of the wavw

Answer 1

The magnetic field in a plane electromagnetic wave is given by: By= 12 x 10

The magnetic field in a plane electromagnetic wave is given by: By= 12 x 10-8 sin (1.20 x 107 z + 3.60 x 10 15 t ) T. Calculate the (i) Energy density associated with the Electromagnetic waves (ii) Speed of the wave.



A)

 

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a)

By = 12 x 10-8 sin [1.20 x 107 z + 3.60 x 1015t]

Now Bo = 12 x 10-8 T and c = 3 x 10 8 m/s

Since Eo =  Bo c = 12 x 10-8 x 3 x 10 8 = 36 V/m

Energy Density = (1/2) ε0Eo2 = (1/2)(8.85 x 10-12) (36x36)

Energy Density = 5.74 x 10-15 J/m3

 

b)

By = 12 x 10-8 sin [1.20 x 107 z + 3.60 x 1015t]

Now k= 1.2 x 107 and w = 3.6 x 1015

Since, λ = (2π / k) and f = (w / 2π)

V = λ x f = kw = 3 x 108 m/s (approx.)

Answer 2

Answer:

The magnetic field in a plane electromagnetic wave is given by: By = 12 * 10 8 sin (1.20 x 10'z + 3.60 x 1015 t) T.