Which type of generator produces current that flows in a single direction?

• A. AC Generator
• B. DC Generator
• C. Both
• D. Neither

Answer: (B)

Direct current is produced by devices that convert mechanical energy into electrical energy with a constant direction of current. In a simple generator, the rotation in a magnetic field induces an emf whose polarity would flip each half turn, causing the current to reverse. A DC generator uses a commutator to switch the connection to the external circuit as the coil rotates, effectively rectifying the output so the current flows in one direction. That unidirectional output is what distinguishes a DC generator from an AC generator, which leaves the polarity to alternate with each half turn. So, the generator that produces current in a single direction is the DC generator.