Terminal Voltages of a flashlight cell?

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The discussion centers on the terminal voltages available when a 6V battery is connected in series with a 1.5V flashlight cell. It is noted that the flashlight cell will burn out if subjected to voltages above 1.5V, leading to the conclusion that terminal voltages should not exceed this limit. However, when connected in series, the total voltage can reach 7.5V, and it is also possible to achieve 4.5V by opposing the two cells. The ambiguity in the question is highlighted, as it could have been clearer about the series connection. Ultimately, the available voltages when using one of each battery in series are 7.5V and 4.5V.
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Homework Statement


A 6V battery us connected in series with a 1.5V flashlight cell. What possible terminal voltages are available?


Homework Equations



V = emf-Ir

The Attempt at a Solution



If the flashlight cell is 1.5V, then I think that it will burn out at voltages above 1.5V. So the available terminal voltages are ≤1.5V
 
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The question is worded a bit ambiguously, but I think I know what they mean.

In your attempt at the solution, you assumed that BOTH pairs of terminals were connected. I think they are asking what would happen if ONE pair of terminals were touching.
 
What the question really means is: You wish to power some devices from a couple of dry cell batteries you have. You can power a 6v gadget from the 6v cell, and a 1.5v gadget from the 1.5v cell. But if you join the two cells in series it's possible to obtain additional voltages, not just the 6v and 1.5v, so you can power other gadgets that require different voltages. What additional voltages can you obtain by powering some gadget using these batteries connected in series?
 
Ohhh... I don't see why they couldn't just say a 6V battery and a 1.5V battery. If they were in series, you could have 7.5V. You can also get 4.5V by running the 1.5V battery against the 6V battery. Are these two voltages the only voltages possible when connecting them in series?
 
carnivalcougar said:
Ohhh... I don't see why they couldn't just say a 6V battery and a 1.5V battery. If they were in series, you could have 7.5V. You can also get 4.5V by running the 1.5V battery against the 6V battery. Are these two voltages the only voltages possible when connecting them in series?
If you have only one of each, that's what you can achieve. Correct.
 
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