Easy MCQ +4 / -1 PYQ · JEE Mains 2021

A plane electromagnetic wave of frequency 100 MHz is travelling in vacuum along the x-direction. At a particular point in space and time, $\overrightarrow B = 2.0 \times {10^{ - 8}}\widehat kT$. (where, $\widehat k$ is unit vector along z-direction) What is $\overrightarrow E$ at this point?

  1. A 0.6 $\widehat j$ V/m
  2. B 6.0 $\widehat k$ V/m
  3. C 6.0 $\widehat j$ V/m Correct answer
  4. D 0.6 $\widehat k$ V/m

Solution

f = 100 MHz<br><br>$\overrightarrow B = 2 \times {10^{ - 8}}T$<br><br>$\overrightarrow E = \overrightarrow B \times \overrightarrow V$<br><br>$= (2 \times {10^8}\widehat k) \times (3 \times {10^8}\widehat i)$<br><br>$= 6(\widehat k \times \widehat i) = 6\widehat j$ V/m<br><br>$\Rightarrow$ $\overrightarrow E = 6\widehat j$ V/m

About this question

Subject: Physics · Chapter: Electromagnetic Waves · Topic: Properties of EM Waves

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