Question bank/JEE Main/Physics

JEE MainPhysicsModerateCapacitance

A fiber sheet with relative permittivity 5 is inserted between
two parallel metal plates 0.25 cm apart. Apotential difference of 2500 v

is applied between the plates. If dielectric strength of air is 3 ×

10^6 v/m then.

Show answer and solution
As V = V_1 + V_2
2500 = 0.0002 E_1 + 0.0023 E_2

2E_1 + 23 E_2 = 25 x 10^6

Also; E_1 = 5E_2


E_1 = 3.788 x 10^6 V/m

As E_1> 3.6 x 10^6 Hence Air will breakdown

Source: Grass-G / P-12 Physics paper 2 Nov.docx

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