KCET · Physics · Electromagnetic Waves
The ratio of the magnitudes of electric field to the magnetic field of an electromagnetic wave is of the order of
- A \(10^{-8} \mathrm{~ms}^{-1}\)
- B \(10^5 \mathrm{~ms}^{-1}\)
- C \(10^{-5} \mathrm{~ms}^{-1}\)
- D \(10^8 \mathrm{~ms}^{-1}\)
Answer & Solution
Correct Answer
(D) \(10^8 \mathrm{~ms}^{-1}\)
Step-by-step Solution
Detailed explanation
As we known,
\(v=\frac{\mathbf{E}}{\mathbf{B}}\) or \(v=\frac{|\mathbf{E}|}{|\mathbf{B}|}\)
For an electromagnetic wave, \(v=c\)
\(\therefore \frac{|\mathbf{E}|}{|\mathbf{B}|}=c=3 \times 10^8 \mathrm{~ms}^{-1}\)
\(\therefore|\mathbf{E}|:|\mathbf{B}|\) is of the order of \(10^8 \mathrm{~ms}^{-1}\).
\(v=\frac{\mathbf{E}}{\mathbf{B}}\) or \(v=\frac{|\mathbf{E}|}{|\mathbf{B}|}\)
For an electromagnetic wave, \(v=c\)
\(\therefore \frac{|\mathbf{E}|}{|\mathbf{B}|}=c=3 \times 10^8 \mathrm{~ms}^{-1}\)
\(\therefore|\mathbf{E}|:|\mathbf{B}|\) is of the order of \(10^8 \mathrm{~ms}^{-1}\).
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