The region in which electric lines of forces are closer, have more value of electric field than the region in which electric lines of forces are farther. (i) Electric lines of forces are closer and uniform, so acceleration on proton is increasing till B, hence proton has maximum velocity at B, therefore p1 is maximum. (ii) In this figure, electric lines of forces are going away from each other, hence electric field continuously decreases, so p2 is moderate at B. (iii) In this figure, electric lines of forces are farthest among all three figures, hence acceleration on proton is minimum due to weakest electric field, hence p3 is minimum at B. ∴ p1>p2>p3