The oscillating magnetic field in a plane electromagnetic wave is given by
`B_(y)=(8xx10^(-6))sin[2xx10^(11)t+300pix]T`
(i) Calculate the wavelength of the electromagnetic wave.
(ii) Write down the expression for the oscillating electric field.

Explanation

(i) Comparing the equation of oscillating electric field with the standard wave equation, we
`therefore ` Wavelength of the electromagnetic wave
`lambda=(2pi)/(k)=(2pi)/(300pi)=(1)/(150)m`
(ii) The electromagnetic wave is propagating long `-ve` direction of x - axis and magnetic field is oscillating along x - axis, hence electric field must be oscillating along z- axis with an amplitude.
`E_(0)=c.B_(0)=3xx10^(8)xx8xx10^(-6)=2.4xx10^(3)Vm^(-1)`
Hence, expression for oscillating electric field is
`E_(z)=2.4xx10^(3)sin[2xx10^(11)t+300pix]Vm^(-1)`.