Question

If 27MHz radio waves penetrate to a depth of 14 cm, how far do 2.8GHz microwaves penetrate? For radio and microwaves, the depth of penetration into the human body is proportional to ?^1/2.

Answer 1

let ''d'' be the penetration depth and is wavelength. then it is given that

d = k

wavelength is inversly propotional to frequency ''f'' and is given as

= c/f

from these two relation, we get , d is inversly propotional f

so d = m / f                                where m = constant

to compare two depths , the relation can be modified as

d₁/d₂ = f₂ / f₁

d₁ = penetration of radio wave = 14 cm

d₂ = penetration of radio wave

f₁ = frequency of radio waves = 27 MHz = 27 x 10⁶ Hz

f₂ = frequency of radio waves = 2.8 GHz = 2.8 x 10⁹ Hz

inserting the values

14/d₂ = (2.8 x 10⁹ )/(27 x 10⁶ )

d₂ = 1.375 cm