JEE Main 2019PhysicsCapacitanceHardMCQ

JEE Main 2019Capacitance Question with Solution

JEE Main 2019 (09 Jan Shift 1)

Question

A parallel plate capacitor is made of two square plates of side a, separated by a distance d da. The lower triangular portion filled with a dielectric of dielectric constant K, as shown in the figure. Capacitance of this capacitor is:

Choose an option

Show full solutionCorrect option: B
Correct answer
BKε0a2dK-1lnK

Step-by-step explanation



Consider a small element at a distance x. It is a two capacitors in series.

dc=dc1×dc2dc1+dc2

dc=ε0.adxxtanθk+d-xtanθ1

dc=ε0K.adx-xtanθK-1+d.k

C=0aε0K.adx-xtanθK-1+d.k

=ε0k.atanθ(K-1)ln-atanθK-1 +d.kd.K

=ε0Ka2dK-1lnK

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About this question

This is a previous-year question from JEE Main 2019, covering the Capacitance chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.