Q&A

Q: If I connect batteries in series to form a loop, what is the voltage between any two points?

A: That’s an very interesting question from my teacher. When you first see it, it might seem a bit strange, and you can’t immediately come up with an answer. In fact, we can understand that the current will be very large in this model, cause the internal resistance of the power source is very small. But the current won’t continuously increase to infinity. So what does the steady state look like?
It’s easy. There are no external components in the circuit other than the batteries, so the only things consuming electrical energy are the internal resistances of batteries. Expressed in terms of a formula, it is


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Therefore, no voltage drop is generated. So the voltage between any two points is 0

If solar cells can be considered constant current sources, then why do the solar panels we buy all specify xV, xW

I suspect that xV,xW are the appropriate operating voltages for the solar panel, simply because most devices on the market require a voltage source rather than a current source, but this needs verification.

By the way, to get a solar panel, I disassembly an ornament but I can’t restore it. To be precise, I know the structure and the position of the components, but reassembling them doesn’t result in normal operation.