Verified Solution • 2025–26 Session moderate

QJEEM21Phd2de: JEE Main 2021 Physics - Class 12 JEEM21Phd2de Solution: A plane electromagnetic wave of frequency 100 MHz is travelling …

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

Multiple Choice Options

  • A 0.6 j^\widehat j V/m
  • B 6.0 k^\widehat k V/m
  • C 6.0 j^\widehat j V/m
  • D 0.6 k^\widehat k V/m

Step-by-Step Verified Solution

f = 100 MHz

B→=2×10−8T\overrightarrow B = 2 \times {10^{ - 8}}T

E→=B→×V→\overrightarrow E = \overrightarrow B \times \overrightarrow V

=(2×108k^)×(3×108i^)= (2 \times {10^8}\widehat k) \times (3 \times {10^8}\widehat i)

=6(k^×i^)=6j^= 6(\widehat k \times \widehat i) = 6\widehat j V/m

⇒\Rightarrow E→=6j^\overrightarrow E = 6\widehat j V/m

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