Can Two Identical Batteries Power Two Bulbs as Brightly as One?

In summary: If the voltage drop is the same for both bulbs, then the brightness should be the same.In summary, the question is whether connecting two identical batteries in series with two identical light bulbs will result in the same brightness as one battery with one bulb. Using the formula for current in a circuit (I=V/R), we can see that both circuits have the same current (0.38 A). Thus, the brightness should be the same in both cases.
  • #1
nophun6
26
0
Hello.
Here is my question: Is it possible to connect 2 identical batteries to make 2 bulbs connected in series light just as brightly as one bulb connected to one battery?

Reasoning: let's say each battery has a voltage of 1.5V and that each light bulb is equal and has a resistance of 4 ohms.
Now in circuit 1, with two identical batteries and bulbs, the current flowing through the circuit would I = (1.5V+1.5V) / (4ohms+4ohms) = .38 A
Now in circuit 2, with one battery and bulb, the current flowing through the circuit would be I = (1.5V) / (4ohms) = .38A

We know that the amount of current flowing through a light bulb determines its brightness, and thus in circuit 2, .38 A is flowing through 2 bulbs, and in circuit 1 the same amount of current is flowing through only 1 light bulb, thus it is not possible,

Can someone tell me if this is right? Much appreciated.
 
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  • #2
Current is continuous through all parts of a series circuit. Consider two bulbs in series: if one bulb has 0.38 A flowing through it, the other must also.

Consider electrons in a wire to behave much like water in a pipe. If some volume of water is flowing through part of a pipe every second, the same volume must be flowing through every other part of the pipe every second.

In the case of (1 bulb, one battery), the bulb drops 1.5V and carries 0.38A of current. In the case of (2 bulbs, 2 batteries), each bulb drops 1.5V and carries 0.38A. Each of those two bulbs would be lit identically to the single bulb, single battery situation.

- Warren
 
  • #3
I think it also depends on what the voltage drop across each bulb (resistor) is.
 

1. Why is my battery draining so quickly?

There could be several reasons for this. It could be due to a faulty battery, a malfunctioning circuit, or excessive power usage from apps or settings on your device. It is best to check your device's battery usage statistics and see if any particular app or setting is using more power than usual.

2. How can I extend the life of my battery?

To extend the life of your battery, you can try turning off unnecessary features such as Bluetooth, Wi-Fi, and Location Services when not in use. You can also lower your screen brightness and use power-saving mode if your device has one. Additionally, avoid letting your battery drain completely before charging it and try to charge it before it reaches 20% capacity.

3. What should I do if my battery won't charge?

If your battery is not charging, try using a different charging cable or adapter. It is also possible that the charging port on your device is dirty or damaged, so try cleaning it with compressed air or a soft cloth. If none of these solutions work, it may be a battery or circuit issue and you should take your device to a professional for repair.

4. How do I know if my circuit is malfunctioning?

If your device is not turning on or is turning off unexpectedly, it could be a sign of a malfunctioning circuit. You may also notice other issues such as flickering screens, slow performance, or frequent overheating. In some cases, a malfunctioning circuit can also cause your battery to drain quickly.

5. Can I replace my own battery or should I take it to a professional?

This depends on the type of device you have and your level of expertise. Some devices have easily replaceable batteries, while others may require special tools and skills to replace. It is always recommended to take your device to a professional for battery replacement, especially if you are unsure of how to do it yourself.

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