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QJEEM22Phf7dc: JEE Main 2022 Physics - Class 12 JEEM22Phf7dc Solution: A capacitor of capacitance 500 F is charged completely using a…

A capacitor of capacitance 500 μ\mu F is charged completely using a dc supply of 100 V. It is now connected to an inductor of inductance 50 mH to form an LC circuit. The maximum current in LC circuit will be _______ A.

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JEE Main 2022 (Online) 29th July Evening Shift Physics - Alternating Current Question 56 English Explanation 1

At steady state charge stored on the capacitor,

qmax⁡=CV{q_{\max }} = CV

=500×10−6×100= 500 \times {10^{ - 6}} \times 100

=5×10−2 C= 5 \times {10^{ - 2}}\,C

JEE Main 2022 (Online) 29th July Evening Shift Physics - Alternating Current Question 56 English Explanation 2

Energy stored in the capacitor,

Umax⁡=qmax⁡22C{U_{\max }} = {{q_{\max }^2} \over {2C}}

Now, when electrostatic energy of capacitor converted to magnetic field energy then all energy of capacitor is transferrd to the inductor.

∴\therefore Maximum energy stored in the inductor

UL max⁡=12L Imax⁡2{U_{L\,\max }} = {1 \over 2}L\,I_{\max }^2

∴\therefore 12L Imax⁡2=qmax⁡22C{1 \over 2}L\,I_{\max }^2 = {{q_{\max }^2} \over {2C}}

⇒Imax⁡=qmax⁡LC\Rightarrow {I_{\max }} = {{{q_{\max }}} \over {\sqrt {LC} }}

=5×10−250×10−3×500×10−6= {{5 \times {{10}^{ - 2}}} \over {\sqrt {50 \times {{10}^{ - 3}} \times 500 \times {{10}^{ - 6}}} }}

=5×10−25×10−3= {{5 \times {{10}^{ - 2}}} \over {5 \times {{10}^{ - 3}}}}

=10 A= 10\,A

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