# Questions tagged [batteries]

Devices to store chemical energy and convert it to electrical energy.

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319 views

### Many cells in parallel

If two or more cells of unequal voltages are connected in parallel (with the same terminal on the same side), is there a formula that gives the net potential difference? Also, by Kirchoff's loop law, ...
69 views

### Why does all the voltage has to be dropped in a circuit?

In a simple circuit with a single resistor the entire voltage provided by the cell drops. It is independent of the resistance. Why does this happen? What is the mechanism behind this? I mean why does ...
179 views

### How the current moves in the battery and outside the battery?

Does it move again to the negative terminal or stays at the positive terminal until the electrons all come .so the voltage will.be zero and current flow .I want simple clear explanation because i am ...
430 views

### If two batteries that are fully charged with opposite polarities and one has higher emf.Does one will charge the other? [closed]

if there are two batteries fully charged in a circuit connected in series and one has higher emf than the other does one charge the other or not ? does any current pass in the circuit ?and if yes ...
163 views

### Quartz piezoelectric battery

I'm designing a battery that uses quartz crystals to hold/produce a current for a long time using piezoelectricity. My question is: Would it be more efficient to have multiple small quartz crystals ...
152 views

### What do the batteries actually do to the electrons?

I am plagued by this simple question that what force exactly causes the motion of an electron in the middle of a lattice of electrons of a wire? a. Is it an electric field created inside a wire due to ...
2k views

### Connecting cells in series and parallel

When 2 cells is connected in series of the same emf like the following: [just the part of the circuit that I need...] The resultant emf will be twice as the previous identical emf. If we reverse ...
54 views

### Is this Thevinin equivalent of a voltage divider, correct?

Found the PDF version of The Art of Electronics (Horowitz and Hill) recently, and, having nothing better to do... I thought I'd give it a read. It wasn't long before I hit a wall (courtesy: my inept ...
409 views

### Why does battery generate less terminal voltage difference when current flows?

The terminal voltage difference of a battery means the difference of voltage between the two termials of a battery. Now, a battery has a voltage at the positive terminal and a voltage at the negative ...
2k views

644 views

### Circuit with three capacitors and a switch [closed]

I have a homework problem where I have a battery connected to a capacitor and a switch that connects the capacitor to 2 others in series/disconnects the circuit from the battery. The question is: ...
520 views

### Why is the voltage in my battery rising?

While playing with some 9 volt batteries in a series circuit, I noticed that the voltage of the battery as measured by my voltmeter was increasing at a constant rate. After placing a bulb in my ...
83 views

### Current in circuits and conductivity

I'm really puzzled with a problem for a rather long time and I can't really seem to be able to solve it at all. It has to do with the electrons that move in a circuit. We know that a battery builds ...
2k views

### Emf of a Cell in an Open Circuit

Consider a cell having terminal voltage $V'$ and EMF, $V$ having internal resistance, $r$ and current, $I$ flows through the circuit in which an external resistance, $R$ is connected. Potential drop ...
1k views

What would the reading be on this voltmeter? Suppose The battery is $5V$. Would the reading be $5V$? If you see it from the other way, the two ends of the voltmeter are connected by ideal wires; ...
16k views

### short circuit an alkaline battery

i'm not doing anything related to physics, but i'm just curious : What really happen when i short circuit an alkaline battery ? some article in the net shown that fire/explosion can be happened when ...
403 views

### Does a higher e.m.f give a larger current?

I was told that e.m.f. is the work done on the charge carriers (i.e. electrons in wires or free ions in electrolytes). Does this mean that e.m.f is preportional to current (the rate of flow of charge)...
230 views

### If a resistance of $0$ ohms and $x$ ohms are in parallel does all current pass through the $0$ resistance? [closed]

If a resistance of $0 \Omega$ and $x$ (and $x>0$) are in parallel does all current pass through the $0$ resistance? For instance in the following circuit: Set variable resistor to o ...
1k views

### How does connecting batteries in series work?

My question may seem naive so please bear with me. I just began learning about circuits and I am having problem seeing how two or more batteries can be connected in series and how the current flows in ...
73 views

### Charge generated by battery or wires?

According to emf concept,we say that due to potential difference between electrodes of battery, electrons or charges want to move to opposite electrode. But electrodes are not joined. So they have to ...
3k views

### Increase in mass of battery of my smartphone [closed]

The charge on my smartphone was zero. I charged my phone to its maximum capacity. How much mass $\Delta m$ did my mobile gained after charging the battery? Maximum capacity of the smartphone's ...
118 views

### Current relationship with different light bulbs

I have a circuit in where there are 3 different bulbs (circular, oval, and rectangular, the circular is the dimmest, the rectangular is more brighter, and the oval is the brightest. Now , I am ...
3k views

### Working of a potentiometer

Why do we achieve a zero deflection situation in the galvanometer when we slide the jockey on the potentiometer wire ? Or what is happening in the secondary circuit that causes zero deflection in ...
184 views

### Parallel combination of batteries [closed]

What is the current through resistance of 6 ohm in the figure. please explain through Kirchoff laws and keep it simple on college level
101 views

### Does this kind of circuit work?

I am going to see if having electric voltage through fruit will slow the decay. So I have my treatment set up here: and I am going to wrap this so that: However, my teacher told me that this might ...
132 views

### No-answers-found Li-Ion battery questions [closed]

Background I've spent almost 7 hours researching about Li-ion batteries because my Galaxy S2 only lasts 2 hours with all turned off and only 40 apps installed (removed system apps and bloatware) and ...
1k views

### Why is the potential drop zero across a wire of zero resistance? [duplicate]

Okay, even if the wire has zero resistance, then charges are being transferred in the direction of electric field, which means there must be a potential drop according to the distance travelled by the ...
2k views

### How is potential difference maintained in a battery?

I am beginning of learn electricity so sorry if my questions are confusing or does not make sense. My question is specifically about how voltage (which I guess is due to separation of uneven charges) ...
273 views

### Simple circuit with mesh current. Two resistors, two batteries [closed]

I can't find current through 6k resistor using mesh-current method. Using KVL on left and right side you get: \begin{align} V_\text{4k} + V_{6k} - 10V =& 0 \tag{left loop}\\ 13V \text{(voltage ...
5k views

### Batteries in series vs parallel

As fa as I understand it, two identicle batteries in parallel will give double the amperage than just one battery and two batteries in series will give double the voltage. If my understanding is ...
3k views

### What is the volume of gases liberated when a battery is charged?

Apparently Hydrogen/Oxygen are liberated when a Lead-acid battery is charged. If true, how does one calculate the expected volume & rate at which each gas is liberated when a battery is charged?
Consider an isolated capacitor (no battery). Since the electrostatic force is conservative, the infinitesimal work done on the capacitor plates can be written as $$\mathrm{d} W=-\mathrm{d} U_e$$ ...