Physics · thermodynamics · first law · modern-physics
Problem
A capacitor (see problem 6.6.26) charged to a potential difference V was discharged by closing the key to zero during the time during which the polarization state of the dielectric did not change, and then the key was opened.
a. What potential difference will be established on the capacitor if the permittivity of the medium is ε?
b. Find how much the temperature of the dielectric will change (ε = 81) during this process. The specific heat capacity of the dielectric is c = 4.18 J/(kg⋅K), its density is ρ = 1⋅10³ kg/m³, the distance between the capacitor plates is d = 1 mm, and the potential difference is V = 300 V. Assume that the dielectric does not exchange heat with the environment.