Question

The positively charged ions are called and the negative ones are called anion. But why the electrodes used in electrolysis have opposite signs, i.e.the electrode having positive sign is known as anode while, the negative electrode is known as cathode?

Answer 1

It is not necessary that cathode is negative. By changing the direction of current we can interchange the polarity of electrodes. In some books cathode is taken as negative electrode whereas in some books anode is considered as negative.