Questions tagged [batteries]
Devices to store chemical energy and convert it to electrical energy.
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Question about amp-hour and batteries in series
I am a little confused about this wiring batteries in series and parallel and the effect of this on total time that these batteries can last(I suppose this is called amp-hour, correct me if I'm wrong) ...
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1answer
25 views
Combining two power sources to get voltage from one and current from another
For a project, I have to make a battery that output 5 V, 500 mA. However, each one of my cells can only produce 1 V, 80 mA. I can combine these cells in series and parallel to get the required ...
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1answer
60 views
Different batteries in a parallel circuit
I have come across this question in my physics textbook. Two batteries are connected in parallel to a resistor (see the above image). The first battery generates $U1 = 9V$ of voltage and its internal ...
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3answers
76 views
RC circuit discharge while being connected to a battery?
I am facing a conceptual problem in analyzing the following situation which was part of a physics exam;
A series RC circuit with $R = 200k \Omega$ and $C = 10 \mu F$ is connected to a 5V battery and ...
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2answers
40 views
What happens when a battery is dead?
While studying circuits I am having a question that when we say a battery is dead.Do we mean that the voltage difference between the ends has become zero?If no,then what actually happens?
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3answers
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Can anyone tell me why the answer to this question is D? [closed]
I think the current will go through earth wire but my physics teacher told us the current will continue to flow through the circuit.
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3answers
64 views
Practical usage of batteries connected in parallel
Is there any practical usage in real devices for connecting batteries in parallel? Or is it more a theoretical construct? It seems to me that only batteries in series are used nowdays.
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2answers
31 views
Empty and fresh battery in series
If you have 2 (e.g. 1.5V) batteries in series and one is dead/empty, what is the reason why a device is not working? Lack of voltage (1.5 + 0 is simply not enough for the device to operate)? From my ...
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2answers
53 views
Why did a 12V battery affect my motor more than two 9v batteries in series?
In class, we made a coil of wire and used it to make a simple electric motor with a magnet. I put two square 9v batteries in series for a total of 18v to power the motor.
I then used a larger 12v ...
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2answers
46 views
The importance and the role of a switch in an electrical circuit
There is this simple test:
Three identical bulbs are connected in the circuit illustrated in the figure. When switch $S$ is closed:
a] The brightness of $A$ and $B$ remains the same, while $C$ goes ...
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2answers
36 views
For a real battery, why is two identical bulbs in parrallel slightly more dim than just one in series
Image for reference:
$$\begin{align}
&r = 0.8\,\Omega\\
&\mathscr{E} = 1.5\,\mathrm V\\
&A = B = 6\,\Omega.
\end{align}$$
The current when the switch is open, the only other resistor is ...
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1answer
27 views
Direct current electric circuit
Why when I reverse one of the three batteries in a torch light, the bulb does not light up?
The three batteries (one of them is reversed) and the bulb suppose to form a closed loop.
According to ...
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1answer
24 views
Why do we subtract the voltage of the resistor from the emf voltage to find the terminal voltage?
I attached an image of a question from homework.
I calculated the current in step 1) and then I calculated the voltage of the resistor. But why do I need to subtract that voltage from the emf voltage ...
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1answer
59 views
Doubt while simulating electric circuits
Today, I was simulating DC electric circuits just for knowledge and fun using PhET interactive simulations. But I'm having trouble understanding these circuits which I made.
I think that both these ...
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2answers
33 views
Voltage when lamp burns out [closed]
In the question below, shouldn't the voltmeter read zero V because the circuit is broken and there is no current flowing? (the answer in the text is 12v)
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1answer
18 views
Question about electrochemical reaction in fuel cell
The electrochemical reaction on the anode side of a fuel cell can be expressed as hydrogen split into hydrogen protons and electrons. I'm doing some research about the electrochemical reaction in a ...
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3answers
73 views
Why doesn't the flow electrons occur in a broken circuit?
Take a battery and connect a small led bulb across it with the help of two wires. The bulb will glow, but if I cut a small piece of wire from any part of the connecting wires,the circuit will not work ...
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1answer
25 views
Intuition behind swapping the known and unknown resistance in a slide wire meter bridge
Today I was learning about wheatstones and balanced meter bridges. But while learning about the sources of error while working with the meter bridge (measuring unknown resistance), I couldn't ...
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2answers
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How do voltmeters measure work done over a component?
In my physics class, we were shown the picture below to measure the current and potential difference through a component. We were told that the resistance of the ammeter is as low as possible, and the ...
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6answers
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Does the resistance of the voltmeter affect the behavior of this circuit?
I have this setup.
It consists of a battery of no internal resistance with voltage $V$ and a resistor with resistance $R$. It also consists of a voltmeter of some (not so large) resistance as good ...
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2answers
49 views
Power in a simple electrical circuit [closed]
In this picture, as we know power due to heating of the resistance is $V^2/R$ .
Now, if we add a parallel resistance to the circuit, the power dissipated through this resistor is also $V^2/R$ ...
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2answers
31 views
Voltmeter connection across motor
I want to measure the voltage(potential difference) acorss the motor A.
Where should I connect the voltmeter?
I am confused between two possibilities:
between X and Y (between two ends of the motor ...
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1answer
23 views
Uncertainty estimation of a quantity after its calibration
I have to calibrate power output of a diode to its input voltage. The voltage source has negligible error but the power meter has significant uncertainty (a couple %). I take a number of power ...
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0answers
22 views
Electronegative - Electropositive atoms can attract ions?
Well I was just wondering how a copper-zinc battery works, with electrolyte an equilibrium of water and NaOH. It says that NaOH is dissolved (I understand that) into water forming H$_4$O$_8$Na+ ions ...
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2answers
46 views
Is (DC/battery) voltage a result of charge? or energy? or both?
Backstory: I’m a software engineer just getting into electronics and it seems that everything I’ve ever been told about electricity my whole life is a candy-coated lie. I can’t find consistent logical ...
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4answers
112 views
How does resistance *really* work? (DC, battery, LED, atoms, electrons)
Backstory: I’m a software engineer just getting into electronics and it seems that everything I’ve ever been told about electricity my whole life is a candy-coated lie. I can’t find consistent logical ...
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1answer
36 views
What is difference between current and voltage? [closed]
If current passes through the bulb not using it up then how battery becomes weak after sometime?
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0answers
36 views
Why are(n’t) rechargeable batteries damaged by partial charging?
Originally asked in ElectricalEngineering.SE, but I was told Physics.SE might be a better place to ask.
Over the years, I've come across websites and people with different opinions on the "correct" ...
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1answer
45 views
Misconception about flow of charges
Let's say I have a 5V battery connected in the manner shown in the diagram. I've tried this setup with all sorts of things like pouring brine(salt water) into the soil to decrease its resistance so ...
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2answers
97 views
Does current flow when you connect a battery to earth?
Let's say that the earth has 0V and everything is ideal,
does current still flow and why?
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5answers
94 views
Potential Difference of a battery - What does it mean?
I have studied current electricity for a while now. When I look back at basic concepts, I am quite clear about what current, electron, resistance is. But I cannot imagine about the potential ...
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3answers
81 views
Electrons and wires [duplicate]
The electrons that carry the electric energy are in wires or in the battery ? battery provides a potential difference but from where electrons flow to make for example a bulb light. If they flow from ...
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2answers
60 views
From where electrons flow to make a bulb light?
Suppose we have the "basic" stuff like a battery 2 piece of wire and a bulb. Battery has a potential difference. But from where electrons flow to make the bulb light? from wire or from battery or from ...
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1answer
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Question about circuit with two cells [closed]
Edited - could someone explain how you treat a circuit with two cells in respect to circuit laws and also whether the section in the middle is in parallel or in series.
Second Edit: I’ve researched ...
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4answers
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How is energy conserved in a theoretical circuit where you put a lightbulb and two rechargeable batteries like… (diagram included)
In the beginning the first battery is fully charged, and the second is fully discharged. As the circuit is connected the discharging battery recharges a dead second battery and light is emitted from ...
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2answers
36 views
What possible advantage could there be in connecting several identical batteries in parallel? [duplicate]
In two-cell flash light,the batteries are usually connected in series. Why not connect them in parallel?
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2answers
77 views
$V = 4 volts$ but $I = 0$
Recently in my school, I tried to generate electricity from plants in a flower pot with copper and Zinc electrodes. The Potential difference in the voltmeter read 2 to 3 volts but when I connected the ...
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0answers
36 views
What force is responsible for the movement of electrons in a current caused by an electrochemical source?
From what I have read, batteries provide an electrochemical potential that causes electrons to move from the negative terminal through a conductor to the positive terminal.
I have read numerous ...
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1answer
22 views
Hydrogen oxygen fuel cells
In hydrogen - oxygen fuel cell, the electrode used is carbon electrode.Hydrogen is passed through through the anode compartment where it is oxidised. Oxygen is passed through the cathode compartment ...
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1answer
37 views
How a battery maintains the current in the circuit? [duplicate]
How a battery maintains the current in the citcuit? Iwant to know each and every step of this process mathematically and theoretically also.
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1answer
33 views
Confusion about calculating resistances & terminal voltage
I'm looking at an exercise where a battery is powering two parallel light bulbs. Given are the battery's EMF ($12.0 V$) and its terminal voltage in this particular circuit ($11.8 V$), as well as the ...
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1answer
45 views
Using a significantly large metallic sphere, could we draw out the electrons from the negative terminal of a battery?
I've pored over many articles on electrochemical cells, and I understand that on the oxidation side of a zinc-copper Daniell cell, the anode is highly negatively charged because zinc participates in ...
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1answer
33 views
How are batteries affected on planes? [closed]
I'm currently an engineer and was fascinated at how technology came to be and how we were able to find out that we can take energy and essentially store it for a later time. I was thinking about ...
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1answer
22 views
In a Radioisotope betavoltaic cell, does the amperage or voltage decay?
In a tritium-powered betavoltaic cell, the power output obviously decreases as the tritium decays. Is it the voltage, amperage, or both that would decay?
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2answers
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Why is the electric potential difference independent of resistance?
According to wikipedia the definition of electric potential difference is as follows:
The difference in electric potential between two points (i.e., voltage) is defined as the work needed per unit ...
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1answer
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is this the reason why current doesn't flow over a resistance if there is another path without resistance? [duplicate]
Let's suppose that a single battery is connected with a wire, which does not have resistance. Electrons will start to flow , in reality, with a wire with resistance, a potential difference would be ...
2
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1answer
68 views
How can a battery 'come back to life'?
Earlier today, one of my family drained our car's battery by accident, by leaving the lights on too long. It wouldn't start at all, so they had to walk back home from where the car was parked (a few ...
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3answers
93 views
What determines the voltage in a battery?
This diagram problem has got me thinking about what determines the voltage in a battery. At school, we were taught this method of giving a value of voltage to points in a circuit. However, I do not ...
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3answers
315 views
Hardest circuit diagram
I have provided an example of the type of problem I am having issues with. In the given diagram, the resistances and batteries are identical and the batteries do not have internal resistances(for the ...
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1answer
60 views
Realistic energy output of a battery
An answer from the post "Battery life with hot and cold wires" talks about Peukert's law related to the battery capacity. Now, within the scope of undergrad electromagnetism courses, the following are ...
