Question

The electric component of a beam of polarized light is Ey = (5.31 V/m) sin[(1.29 × 106 m-1)z + ωt]. (a) Write an expression for the magnetic field component of the wave, including a value for ω. What are the (b) wavelength, (c) period, and (d) intensity of this light? (e) Parallel to which axis does the magnetic field oscillate? (f) In which region of the electromagnetic spectrum is this wave?

Answer 1

Ey = (5.31V/m)sin[(1.29 × 106)z + ωt]

Emax = 5.31 V/m

c = 3*10^8 m/s

Bmax = Emax/c = 5.31/(3*10^8)

Bmax = 1.77*10^-8 T

k = 1.29*10^6

w= c*k = 3*10^8*1.29*10^6

w = 3.87*10^14 rad/s

(a) Bx = (1.77*10^-8 T)sin[(1.29*10^6 m^-1)z + (3.87*10^14 s^-1)t]

(b) k = 1.29*10^6= 2*3.14/lamda

lamda = 4.868*10^-6 m

(c) w = 3.87*10^14 = 2*3.14/T

T = 1.623*10^-14 s

(d) I = (1/2)eoE^2c

I = 0.5*8.85*10^-12*5.31^2*3*10^8

I = 0.0374 W/m^2

(e) parallel to x axis

(f) lamda = 4.868*10^-6 m

lamda = 5 um

the region of spectrum is infared wave