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QJEEM23Ph9236: JEE Main 2023 Physics - Class 12 JEEM23Ph9236 Solution: As shown in figure, a cuboid lies in a region with electric…

As shown in figure, a cuboid lies in a region with electric field E=2x2i^−4yj^+6k^ N/CE=2 x^{2} \hat{i}-4 y \hat{j}+6 \hat{k} \mathrm{~N} / \mathrm{C} . The magnitude of charge within the cuboid is n∈0Cn \in_{0} C .

The value of nn is _________ (if dimension of cuboid is 1×2×3 m31 \times 2 \times 3 \mathrm{~m}^{3} )

JEE Main 2023 (Online) 30th January Evening Shift Physics - Electrostatics Question 78 English

Step-by-Step Verified Solution

Flux through planes parallel to y−z=2(1)2×y-z=2(1)^{2} \times Area

amp;=2(1)2×2×3amp;=12Nm2/C\begin{aligned}& =2(1)^{2} \times 2 \times 3 \\\\& =12 \mathrm{Nm}^{2} / \mathrm{C}\end{aligned}

Flux through planes parallel to x−z=−4(2)×x-z=-4(2) \times Area

amp;=−4(2)×1×3amp;=−24Nm2/C\begin{aligned}& =-4(2) \times 1 \times 3 \\\\& =-24 \mathrm{Nm}^{2} / \mathrm{C}\end{aligned}

Flux through planes parallel to x−y=0x-y=0

⇒ϕ\Rightarrow \phi Total =12−24=−12=12-24=-12

⇒−12=qencε0⇒∣qenc∣=12ε0\Rightarrow-12=\frac{q_{\mathrm{enc}}}{\varepsilon_{0}} \Rightarrow\left|q_{\mathrm{enc}}\right|=12 \varepsilon_{0}

⇒n=12\Rightarrow n=12

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