I Think you,ll have to expand your question , what do you exactly mean by "cheaper"
The main target of AC AND DC IS TO GIVE SUUPLY TO CONUMERS WERE AS AC CURRENT IS CHEAPER COMPARING WITH DC
It produces alternating current AC. It is cheaper to build than a DC or an AC - DC welder. Most electrodes can be used with DC. Some can be used for both. Very few are AC only. DC produces a smoother arc, is easier to strike an arc and most machines in industry are DC. Surprisingly a lot of AC machines are on farms as they were cheaper to buy.
AC is easier and cheaper to send from the generators to the consumers than DC is.
some things requre a dc (direct current) rather than an ac (alternating current)
because the transmission cost of ac supply is lesser than dc. thats why ac is prefered
A "Rectifier" converts AC current to pulsating DC current.
no actually dc current is more dangerous than ac because dc is a direct current and has no current zero condition ,which is very dangerous and do not leave us if we get shock while ac current leave us when we get shock
AC means alternating current DC means direct current there is no polarity reversal
AC current is not necessarily faster than DC current. The speed of current flow depends on the specific characteristics of the circuit and the components involved, rather than the type of current being used.
There's no correlation between the voltage, the current, and whether the source is AC or DC.
DC, or direct current, is stronger than AC, or alternating current. The reason for this is because DC current is smooth and unvariable as opposed to AC which varies from zero to whatever the maximum is, and then goes back to zero once again.
A dc welder is a lot cheaper by fair of the two