Final answer:
Batteries and thermocouples produce a voltage that drives a direct current (DC) in a circuit, and the current flow is proportional to the applied voltage according to Ohm's Law.
Step-by-step explanation:
The types of current that result from voltage produced by batteries and thermocouples are typically direct current (DC). Batteries provide a constant voltage and, when connected in a circuit, drive a current in one direction from the negative to the positive terminal. Thermocouples also produce a direct (steady) voltage when there is a temperature difference across the junctions, which in turn can drive a direct current through an external circuit. Ohm's Law states that the current flowing through a conductor is directly proportional to the voltage applied across it, assuming the resistance remains constant.