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8. Electromagnetic waves — Physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 SciencePhysics8. Electromagnetic waves1 Mark
MCQ
For an electromagnetic wave travelling in free space, the relation between average energy densities due to electric $\left( U _{ e }\right)$ and magnetic $\left( U _{ m }\right)$ fields is
  • ✓
    $U _{ e }= U _{ m }$
  • B
    $U _{ e }> U _{ m }$
  • C
    $U _{ e }< U _{ m }$
  • D
    $U _{ e } \neq U _{ m }$
✓

Answer

Correct option: A.
$U _{ e }= U _{ m }$
a
In $EMW$, Average energy density due to electric $\left( U _{ e }\right)$ and magnetic $\left( U _{ m }\right)$ fields is same.

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