From @JohnDenker: Figures 31.13, 31.24, and especially 31.47 show short circuits.
As far as I can tell, nowhere does the text so much as hint
that this might be a bad idea. This is a safety issue, because
sometimes batteries will explode if you short them.
In connection with figure 31.47, there is nothing to keep
people from reversing one of the batteries, whereupon you
have a big battery overdriving a small battery, which is
just about the worst case scenario.
Seriously, you SHOULD NOT draw diagram of short circuits
as if that were a normal thing to do. If you want to draw
one or two such diagrams to define the concept, fine, but
be sure to put skull-and-crossbones warnings all over them.
In any case there should be warnings in the text, saying
that's a bad thing to do, and explaining why.
Also, the batteries aren't the only thing you need to worry
about. A short circuit can overheat the wires. If you want
to put a positive spin on it, mention that in an emergency
situation, if you don't have any matches, you can start a
fire using a 9V battery and some steel wool.
The repeated statements on page 815 that there is no voltage
drop or power dissipation in wires was wrong to begin with.
In the case of a short circuit, it's obviously wrong and
dangerously wrong.
From @JohnDenker: Figures 31.13, 31.24, and especially 31.47 show short circuits.
As far as I can tell, nowhere does the text so much as hint that this might be a bad idea. This is a safety issue, because sometimes batteries will explode if you short them.
I'm sure you can find "some" batteries that don't explode, but the text doesn't explain how to make sure of that ... and the fact remains that even if some of them don't, some of them do. http://weird-diseases.blogspot.com/2014/06/blast-injury-due-to-pencil-battery.html
In connection with figure 31.47, there is nothing to keep people from reversing one of the batteries, whereupon you have a big battery overdriving a small battery, which is just about the worst case scenario.
Seriously, you SHOULD NOT draw diagram of short circuits as if that were a normal thing to do. If you want to draw one or two such diagrams to define the concept, fine, but be sure to put skull-and-crossbones warnings all over them.
In any case there should be warnings in the text, saying that's a bad thing to do, and explaining why.
Also, the batteries aren't the only thing you need to worry about. A short circuit can overheat the wires. If you want to put a positive spin on it, mention that in an emergency situation, if you don't have any matches, you can start a fire using a 9V battery and some steel wool.
The repeated statements on page 815 that there is no voltage drop or power dissipation in wires was wrong to begin with. In the case of a short circuit, it's obviously wrong and dangerously wrong.