Let σ be the uniform surface charge density of two infinite thin plane sheets shown in figure. The electric fields in the three regions I, II and III are:

Question

G1 Physics · Accepted Answer

Each positively charged infinite sheet produces field σ/(2ε₀) on either side, directed away from the sheet. Between the sheets the two fields cancel. Outside, they add. Taking +n̂ to the right gives E(I)=-(σ/ε₀)n̂, E(II)=0, E(III)=(σ/ε₀)n̂.