Question

A cell phone emits a 1.9 GHz electromagnetic wave. Ata location near the phone, the intensity of the wave is measured to be 0.067 W/m2 10 pt What is the amplitude of the electric field at this lo- cation? (in N/C) 18. AO 2.91 BO 3.64 EO 7.11 CO 4.55 FO 8.88 DO 5.69 GO 1.11 x 10 HO 139 x 10 part]What is the amplitude of the magnetic field at this location? (in T) 19. AO 2.37 × 10-8 BO 3.15 x 10-8 CO 4.19 x 10-8 DO 5.57 × 10-8 EO 7.41 × 10-8 FO 9.86 × 10-8 GO 1.31 × 10-7 HO 1.74×10-7

Answer 1

18.

Intensity = I = 0.067 W/m²

$\varepsilon _{0} E^{2}/2 = I/C$

Therefore

2 21

Where $\varepsilon _{0$ = 8.85 x 10^-12, C =speed of light = 3x10⁸

putting values we get

E² = 50.47

therefore , = 7.1 N/C

E- V50.47

option (E) is correct here.

19.

$B = \frac{E}{C} =$

option (A) is correct