2.27 Consider the imaginary rectangular box shown in

Fig. P2.27. A wave traveling in the medium has electric

and magnetic fields

E = 100e -20y cos (27 x 10°t - 40y)

(V/m),

H = -20.64e-20y cos(2 x 10°t-40y-36.85°)

(A/m).

The box has dimensions a = 1 cm, b = 2 cm, and

c=0.5 cm. Determine: (a) the net time-average power

entering the box, (b) the time-average power exiting the

box, and (c) the time-average power absorbed by the

box.

Figure P2.27: Imaginary rectangular box of

Problem 2.27.