9 0 ° ▁“ V ” - gro ove ▁into ▁the ▁bottom ▁edge ▁of ▁the ▁c ath ode . ▁The ▁gro ove ▁weak ens ▁the ▁structure ▁of ▁the ▁co pper ▁growing ▁at ▁the ▁bottom ▁edge ▁of ▁the ▁c ath ode ▁plate ▁because ▁the ▁co pper ▁cry st als ▁grow ▁per pend icular ▁to ▁the ▁c ath ode ▁plate ▁from ▁opposite ▁sides ▁of ▁the ▁gro ove , ▁causing ▁them ▁to ▁intersect ▁at ▁right ▁angles ▁to ▁each ▁other . ▁A ▁dis continu ity ▁in ▁the ▁structure ▁is ▁formed ▁at ▁the ▁intersection ▁that ▁results ▁in ▁a ▁weak ▁zone , ▁along ▁which ▁the ▁co pper ▁spl its ▁during ▁stri pping . ▁ ▁Figure ▁ 4 ▁is ▁a ▁mic ros cope ▁view ▁of ▁the ▁cross - section ▁a ▁co pper ▁c ath ode ▁growing ▁at ▁the ▁tip ▁of ▁a ▁c ath ode ▁plate . ▁The ▁yellow ▁lines ▁show ▁the ▁orientation ▁and ▁direction ▁of ▁cry stal ▁growth . ▁ ▁Low - res istance ▁c ath odes ▁ ▁The ▁standard ▁Isa ▁Process ▁c ath odes ▁have ▁slightly ▁higher ▁elect rical ▁resistance ▁than ▁solid - co pper ▁h anger ▁bar ▁systems ▁used ▁by ▁the ▁K idd ▁Process , ▁meaning ▁that ▁there ▁is ▁a ▁higher ▁power ▁cost . ▁However , ▁this ▁cost ▁is ▁offset ▁by ▁greater ▁reli ability ▁and ▁predict ability ▁in ▁the ▁increase ▁in ▁resistance ▁over ▁time , ▁allowing ▁for ▁maintenance ▁planning . ▁ ▁The ▁solid - co pper ▁h anger ▁bars , ▁on ▁the ▁other ▁hand , ▁lose ▁elect rical ▁performance ▁over ▁a ▁shorter ▁period ▁of ▁time ▁due ▁to ▁cor