LIVE Course for free

Rated by 1 million+ students
Get app now
0 votes
in General by (30.0k points)
closed by
For a good conductor, the depth of penetration of electromagnetic wave is given by:
1. \(\delta = {\left[ {\frac{2}{{\omega \sigma \mu }}} \right]^{\frac{1}{2}}}\)
2. \(\delta = {\left[ {\frac{1}{{\omega \sigma \mu }}} \right]^{\frac{1}{2}}}\)
3. \(\delta = {\left[ {\frac{2}{{\omega \sigma^2 \mu }}} \right]^{\frac{1}{2}}}\)
4. \(\delta = {\left[ {\frac{2}{{\omega \sigma }}} \right]^{\frac{1}{2}}}\)

1 Answer

0 votes
by (54.3k points)
selected by
Best answer
Correct Answer - Option 1 : \(\delta = {\left[ {\frac{2}{{\omega \sigma \mu }}} \right]^{\frac{1}{2}}}\)


The depth of penetration δ of a plane electromagnetic wave incident normally on a good conductor is mathematically defined as:


α is the attenuation constant given by:


For a conducting medium σ >>1. The above expression for the attenuation constant can, therefore, be approximated as:


∴ The attenuation constant becomes:

\(α=\omega \sqrt{\left(\frac{\muσ}{2\omega}\right)}\)

\(α=\sqrt{\left(\frac{\omega\muσ} {2}\right)}\)  or  \(\therefore~\alpha =\sqrt{\pi f\muσ}\)

We know that,


Thus, the skin depth becomes:
\(\delta= [\frac{2}{\omegaσ\mu }]^\frac{1}{2}\)  or  \(\delta=\frac{1}{\sqrt{\pi f \muσ}}\)

  • The skin depth is inversely proportional to the square root of frequency.
  • It is inversely proportional to the square root of the conductivity of the medium.
  • It is inversely proportional to the square root of the permeability of the medium.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.