Задача 31096.

Flat dielectric filled capacitor and its plate filed certain potential difference. Its energy is then equal to 2 x 10 -5 J. After the capacitors are disconnected from the voltage source, insulator removed from the condenser. The work had to make against the forces of the electric field to remove the insulator, is 7 × 10 -5 J. Find the permittivity of the dielectric.

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