Q.

An electromagnetic wave of frequency 100 MHz propagates through a medium of conductivity,σ=10mho/m. The ratio of maximum conduction current density to maximum displacement current density is ______.

[Take 14πε0=9×109N m2/C2]           [2026]


Ans.

(1800)

A

jc=σE

EE0sin(ωt-kx)

jc=σE0sin(ωt-kx)

(jc)max=σE0    ...(i)

Jd=idA=1A×ε0AdEdt

=ε0×E0ωcos(ωt-kx)

(jd)max=ε0E0ω    ...(ii)

(i)/(ii)

(jc)max(jd)max=σE0ε0ωE0σε0ω

10×4π×9×1092π×100×106

1800