$18.1 Conductors in electric field $18.1 Conductors in electric field Van De graaff electrostatic generator 6
6 + + + + + + + + + + q − q − − − − − − − q + + + + + + + + + + + + + + + + q − q − − − − − − − §18.1 Conductors in electric field Van De Graaff electrostatic generator §18.1 Conductors in electric field
$18.1 Conductors in electric field Exercise 1: @o, ob and s is conductor wn. find the and G12G3 Charge conservation OS+O2S=2 1 S G3S+o=Q(2) Q Q The electrostatic equilibriu E B1 0(3) 28282828 十 十 P? 0(4) 280280280 280 $18.1 Conductors in electric field The results are ductor 2a + 2b o1 O 2S 2a-2b S 2S PI Q f 2>0,0<0,2=g G1=O4=0 There are no charg on the outboard surface ,=-03==a=σ S of the conductors
7 Exercise 1: Qa, Qb and S is known, find the σ1, σ2, σ3, and σ4. + σ 1 σ 2 σ 3 σ 4 Qa a b S Qb • • P1 P2 conductor (2) (1) 3 4 1 2 b a S S Q S S Q + = + = σ σ σ σ Charge conservation 0 (3) 2 2 2 2 0 4 0 3 0 2 0 1 1 = − − − = ε σ ε σ ε σ ε σ EP 0 (4) 2 2 2 2 0 4 0 3 0 2 0 1 2 = + + − = ε σ ε σ ε σ ε σ EP The electrostatic equilibrium §18.1 Conductors in electric field S Q Q S Q Q a b a b 2 2 2 3 1 4 − = − = + = = σ σ σ σ + σ 1 σ 2 σ 3 σ 4 Qa a b S Qb • • P1 P2 The results are conductor If Qa > Qb < Qa = Qb 0, 0, σ σ σ σ σ = − = = = = S Qa 2 3 1 4 0 There are no charges on the outboard surface of the conductors. §18.1 Conductors in electric field