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JEE Main 2025 (7 Apr, Shift 2) · Energy Density & Intensity

Energy Density & Intensity question from JEE Main 2025 (7 Apr, Shift 2)

Q5JEE Main 2025 · 7 APR · SHIFT 2Medium

Energy Density & Intensity

The unit of 2Iε0c\sqrt{\frac{2I}{\varepsilon_0 c}} is:

(I = intensity of an electromagnetic wave, c = speed of light)

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Answer: (b)

  1. I=12ε0cE02⇒2Iε0c=E0I = \tfrac{1}{2}\varepsilon_0 c E_0^2 \Rightarrow \sqrt{\dfrac{2I}{\varepsilon_0 c}} = E_0
  2. So the expression is an electric field, with unit N C−1^{-1} (same as V m−1^{-1}).
  3. So the answer is (b) NC−1^{-1}.
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