Physics · 2019
JEE Main · 11 January 2019, Shift 2 · Q22
A 27 mW laser beam has a cross-sectional area of 10 mm^2. The magnitude of the maximum electric field in this electromagnetic wave is given by:…
A $\displaystyle 27$ mW laser beam has a cross-sectional area of $\displaystyle 10 \mathrm{~mm}^2$. The magnitude of the maximum electric field in this electromagnetic wave is given by :
[Given permittivity of space $\displaystyle \epsilon_0=9 \times 10^{-12}$
SI units, Speed of light $\displaystyle \mathrm{c}=3 \times 10^8 \mathrm{~m} / \mathrm{s}$ ]
Official answer
(1)
$\displaystyle 1.4 \mathrm{kV} / \mathrm{m}$
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JEE Main 2019 Physics question, with the answer from NTA’s final answer key. Where our answers come from.