Summary
An A.C. generator converts mechanical energy into electrical energy by rotating a coil in a magnetic field, inducing an electromotive force (e.m.f) and generating alternating current (A.C.).
- A.C. Generator — a device that converts mechanical energy into electrical energy by rotating a coil in a magnetic field. Example: A power plant generator.
- Slip Rings — components that maintain a continuous electrical connection between the rotating coil and the external circuit. Example: Used in A.C. generators to allow the coil to rotate freely.
- Electromotive Force (e.m.f.) — the voltage generated by the movement of a coil in a magnetic field. Example: The voltage induced in the coil of an A.C. generator.
Exam Tips
Key Definitions to Remember
- A.C. Generator: A device that converts mechanical energy into electrical energy.
- Slip Rings: Components that maintain electrical connection in rotating systems.
- Electromotive Force (e.m.f.): Voltage generated by movement in a magnetic field.
Common Confusions
- Confusing slip rings with commutators, which are used in D.C. motors.
- Assuming the current direction does not change in an A.C. generator.
Typical Exam Questions
- What is the function of an A.C. generator? It converts mechanical energy into electrical energy.
- How do slip rings function in an A.C. generator? They maintain a continuous electrical connection with the rotating coil.
- What happens to the current direction in an A.C. generator? It changes direction with each half rotation of the coil.
What Examiners Usually Test
- Understanding of how an A.C. generator works.
- The role of slip rings in maintaining electrical connections.
- The concept of induced e.m.f. and how it relates to coil rotation.