Home/ Questions/Q 1033845
Next
Answered

Quearn Latest Questions

jangyasinni
  • 0
  • 0
Poll
Teacher
Asked: 2024-08-28T20:05:18+05:30 In:

Find the magnitude of the displacement current density in air at a frequency of 18GHz in frequency domain. Take electric field E as 4 units.

  • 0
  • 0

Poll Results

0%a) 18 ( 0 voters )
0%b) 72 ( 0 voters )
0%c) 36 ( 0 voters )
100%d) 4 ( 1 voter )
Based On 1 Vote

Participate in Poll, Choose Your Answer.

poll

    You must login to add an answer.

    Need An Account,

    3 Answers

    1. prasanjit
      Teacher

      d) 4

      Explanation: Jd = dD/dt = εdE/dt in time domain. For frequency domain, convert using
      Fourier transform, Jd = εjωE. The magnitude of
      Jd = εωE = ε(2πf)E. On substituting, we get 4 ampere.

        • 0
    2. jangyasinni
      Teacher

      d

      Explanation: Jd = dD/dt = εdE/dt in time domain. For frequency domain, convert using

      Fourier transform, Jd = εjωE. The magnitude of

      Jd = εωE = ε(2πf)E. On substituting, we get 4 ampere.

        • 0
    3. Quearn
      Best Answer
      Quearnist

      To find the magnitude of the displacement current density ((J_d)) in air for a given frequency, you use the relation for displacement current density in the frequency domain, which is given by the formula

      [ J_d = jomegaepsilon E ]

      Where:

      – (J_d) is the displacement current density.

      – (j) represents the imaginary unit (sqrt(-1)).

      – (omega) is the angular frequency, obtained from (2pi f), with (f) being the frequency in hertz.

      – (epsilon) is the permittivity of the medium (for air, it’s close to the permittivity of free space (epsilon_0 = 8.854 times 10^{-12} F/m)).

      – (E) is the magnitude of the electric field.

      Given:

      – Frequency, (f = 18 , GHz = 18 times 10^9 , Hz)

      – Electric field, (E = 4) units.

      First, calculate (omega):

      [ omega = 2pi f = 2pi times 18 times 10^9 ]

      [ omega approx 113.1 times 10^9 , rad/s ]

      Now, substitute (omega), (E), and (epsilon_0) into the (J_d) formula:

      [ J_d = jomega

        • 0