Final answer:
Electric generators convert mechanical work into electrical energy by rotating a coil in a magnetic field, inducing an electromotive force (emf) and generating an electric current.
Step-by-step explanation:
Electric generators store electric current by converting mechanical work into electric energy. They achieve this by rotating a coil in a magnetic field, which induces an electromotive force (emf) in the coil. This emf drives an alternating current (AC) through the coil, which can be used to power electrical devices.
For example, a water wheel can be used to rotate a magnet, which in turn induces an emf in a nearby wire coil. This emf can then be used to light a light bulb or power other electrical devices.
In summary, electric generators convert mechanical work into electrical energy by rotating a coil in a magnetic field, thereby inducing an emf and generating an electric current.