818.2 The dielectric in the electric field For instance: put a dielectric slab in the two conductor o -Q planes with charge +o and-2, respectively The electric field in the dielectric E<E We can prove that E <E EE K is called dielectric constant E=Keo is called permittivity of dielectric. 818.3 Capacitors and Capacitance Capacitor A capacitor is a device of storing the charges and the electric energy Two conductors, isolated electrically from each other and from their surroundings form a capacitor. Electric field lines9 For instance: put a dielectric slab in the two conductor planes with charge +Q and –Q, respectively. E < E0 The electric field in the dielectric + + + + + + + − − − − − − − + + + + + − − − − − E0 r E′ r E r E′ r + Q − Q We can prove that 0 0 0 ε σ κε σ E = < E = κ 0 ε = ε κ is called dielectric constant. is called permittivity of dielectric. §18.2 The dielectric in the electric field §18.3 Capacitors and Capacitance 1. Capacitor A capacitor is a device of storing the charges and the electric energy. Two conductors, isolated electrically from each other and from their surroundings, form a capacitor