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How should the ends of a generator's coil be joined to the outside circuit to give an alternating…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
- How should the ends of a generator's coil be joined to the outside circuit to give an alternating current, and to give a direct current?
- How do the graphs of the two currents look?
- The coil of a DC generator turns times a second. How many humps does its graph show each second?
Need a reminder? The key ideaShow
A generator turns a coil in a magnetic field. With slip rings it gives alternating current (AC), which changes direction twice in every turn; with a split ring it gives a pulsing direct current (DC). Frequency = turns each second, in hertz; one cycle takes .
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. (a) For AC, the ends go to two complete slip rings. For DC, they go to the two halves of a split ring, which swaps the connections every half turn.
Step 2. (b) AC is a wave above and below zero. DC from a split ring is a row of humps, all above zero.
Step 3. (c) One hump each half turn: humps a second.
Answer: slip rings for AC, a split ring for DC; a wave, and humps; humps each second.
Check. The split ring turns every downward half of the wave into an upward hump, so the humps come twice as often as the turns.
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