Physics · 2021
JEE Main · 17 March 2021, Shift 2 · Q25
Seawater at a frequency f=9 × 10^2 Hz, has permittivity ε=80 ε_0 and resistivity ρ=0.25 Ω m. Imagine a parallel plate capacitor is immersed in…
Seawater at a frequency $\displaystyle f=9 \times 10^2 \mathrm{~Hz}$, has permittivity $\displaystyle \varepsilon=80 \varepsilon_0$ and resistivity $\displaystyle \rho=0.25 \Omega \mathrm{~m}$. Imagine a parallel plate capacitor is immersed in seawater and is driven by an alternating voltage source $\displaystyle \mathrm{V}(\mathrm{t})=\mathrm{V}_0 \sin (2 \pi f \mathrm{t})$. Then the conduction current density becomes $\displaystyle 10^x$ times the displacement current density after time $\displaystyle \mathrm{t}=\frac{1}{800} \mathrm{~s}$. The value of $\displaystyle x$ is
\_\_\_\_.
(Given : $\displaystyle \frac{1}{4 \pi \varepsilon_0}=9 \times 10^9 \mathrm{Nm}^2 \mathrm{C}^{-2}$ )
Official answer
6
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JEE Main 2021 Physics question, with the answer from NTA’s final answer key. Where our answers come from.