Questions tagged [batteries]
Devices to store chemical energy and convert it to electrical energy.
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Electric field of battery
What happen when a charge particle is kept between the two electrodes of battery ?
Will the electric field between those two electrode affect that charged particle?
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Fully charged capacitor is connected to another battery
Suppose an empty capacitor with a capacitance A Farad is connected to a B voltage battery. After the capacitor is fully charged, ...
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Why does taking one current from any cell work?
$\text{We were doing problems on Kirchoff's Laws in my class. The problem :}$
My Professor told that from $B_1$ current $i_1$ is flowing which splits into $i_2,i_3⇒i_1=i_2+i_3$.
Then he used Kirchoff'...
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Confusion on Voltage across a battery
If I have a battery that is 0.1m in length, with the positive and negative terminals situated at the top and bottom, and I am trying to calculate the voltage (electric potential difference, Vdelta = ...
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Can potential at the terminal of a resistor directly connected to negative terminal be non zero?
what will be the potential difference between point a and b?
I have been trying to solve this problem for a long time but couldn't. It has been suggested to solve this problem considering the ...
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Resistance-capacitance (RC) circuit
My textbook says: "This continues until the voltage across the capacitor matches the emf of the battery"
If I were to have a resistor in series with a capacitor, would the voltage across the ...
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Grounding in Circuits [closed]
The question is to find the current through the 8 Ω resistor. My textbook says that it is 3A as there is 0 potential at points "a" and "b" and thus it must drop by 24 V across the ...
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Why is there an electric field around this closed electric circuit?
I have difficulty understanding the picture below. I can understand the green magnetic fields. But why is there an outside, red, electric field? Isn't the electric field guided entirely through the ...
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Understanding voltage as a relative measure between two bodies
Voltage, electric potential difference, electric pressure or electric tension is the difference in electric potential between two points, which (in a static electric field) is defined as the work ...
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Potential difference in circuit of dry cell [duplicate]
I referred to this question potential difference but had a few doubts as to why do electrons move in a circuit? What exactly causes them to do so? And what is
the chemical reaction in the cell which ...
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Is every finite circuit "solvable" using Ohm's law and Kirchhoff's loop rules? [duplicate]
Whenever I have solved circuits (only cells, resistors and wires), it has only been necessary to use Ohm's law (or things derived from Ohm's law, such as how two resistors $R_1$ and $R_2$ have ...
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Why is the current equal when the resistors are in series? [duplicate]
I am a High schooler.
And I learned that the current is always the same when the resisters are in series.
I was told about the water analogy.
If the first one had had a smaller resistance wouldn't it ...
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What is a cathode and an anode in general sense
i am totally confused and not able to understand the difference between cathode and anode
Cathode is defined as reduction point but why is its sign -ve in a terminal and different in a battery
Anode ...
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What will be the minimum time to fully recharge this battery?
There is a rechargeable battery of EMF $ε$, internal resistance $r$ and battery capacity (after full charge) $b$ (Ah).
The fully charged battery is connected to a light bulb for $t$ hours with specs $...
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Would this theoretical battery be practical: 2 charged objects close to one another? [closed]
Consider a system which stores energy by forcing two charged objects (of the same charge) close to one another. When the energy needs to be used, a latch could open and the objects would accelerate ...
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Dependence of field generated by a battery on the geometry of wire/resistor
Introduction: Resistance for a uniform cylindrical$^1$ thing in which "field is uniform and along the cylinder" (this can be equivalently replaced by "the same potential difference is ...
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Can a 9 V battery kill you?
Suppose I connect a 9 V DC battery to a DC-to-AC converter. Then connect the output of the converter to a step-up transformer, which increases the voltage to 2000 V. Now, if I put myself between the ...
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Why can you shortcircuit a car battery with a wrench in your hand and stay safe?
In this demonstration by Prof. Walter Lewin a car battery is shortcircuited with a wrench. The experimenter is holding the wrench in its bare hands, so why he is not experiences an electric shock? ...
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Does electron current flow through inside a battery when connected to an electrical load?
Many popular science sites display and describe that current flows through and inside a battery when connected into an electrical circuit.
But what then prevents current flowing inside the battery ...
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EMF of source depends on the charge and the path then what do we mean when we say EMF of a source is $\epsilon$?
EMF of an EMF source (a battery for example) is defined as the work done by the non-conservative force(s) on charged particles as it passes through the terminals of the source divided by the charge of ...
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Does Resistance Affect Voltage?
I have looked this up and what followed was that resistance does not affect the voltage of a circuit. But lets say we have a power source of 5V flowing at 1 Amp. The neccesary resistance of this ...
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How does higher concentration leads to higher internal resistance in the cell?
Concise Physics mentions that:
Higher the concentration of the electrolyte greater is the internal
resistance(in a cell).
I think that higher the concentration of the electrolyte higher would be the ...
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How does emf depends on material of electrode? [closed]
Concise Physics mentions that:
The emf (electromotive force)of a cell depends on 1) the material of the electrodes and 2)the electrolytes used in the cell.However it is independent of the a)the shape ...
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Is the reason why a normal battery ran out of "juice" that it has reached electrostatic equilibrium between its two terminals?
If we connect a normal battery to a load circuit, its stored electric potential energy on its two terminals (+) & (-) will be consumed by work done on the load and eventually the battery is "...
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Negative reading in voltmeter
Why does the voltmeter shows negative reading when connected in reverse order? What does it mean by negative voltage? Should we say voltage drop across $R2$ is $+12V$ or $-12V$? How to apply Kirchoff'...
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Applying KVL to batteries with different EMF in parallel
Consider the circuit diagram below-
Two batteries of different voltages are placed in
parallel, however as I was told that KVL is applicable to all loops if there is no varying magnetic fields, ...
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Why do the electrons from the 20 V battery not flow into that of the 4V battery in the given circuit?
In this circuit, no electrons will flow between B and C. But I think otherwise. I think that electrons from the negative terminal of the $20V$ battery must also go into the positive terminal of the $...
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Time-reversal in a simple current loop
In classical physics, time and velocity change sign under time-reversal while position, acceleration and force do not. An accelerating particle going to the right becomes a decelerating particle going ...
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Equivalent EMF of unequal cells connected in parallel
I'm aware of the formula to calculate equivalent EMFs of 2 cells connected in parallel as shown in the top figure. But what happens if we switch the polarity of one of the cells? Shouldn't the ...
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How does current get reduced in resistor?
How does the resistor reduce the current? I know that when there is no resistor in the circuit the current is higher than the current when there is a resistor.
But, my question is:
How the resistor ...
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Does charged Li-on battery burn more than discharged one if damaged? [closed]
I am wandering if a charged Li-on battery burns more than discharged one if damaged, considering that the charged one has more energy in it. Thanks.
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Confusion In Fundamental Properties Of A Battery
Ever since I started reading about electrostatics and current electricity I have gotten ever so confused by various things. After watching video lectures by several different people and reading ...
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How long does a headphone last on a given battery? [closed]
Sennheiser HD 598 has 50Ω impedance. It has a 3.6mm cable, but I am planning to do a simple DIY project to replace the cable with a bluetooth receiver, a 3.7V 1000mAh battery (and a charging board).
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Can I apply Kirchhoff's current law to two separate nodes which are connected only by an ideal wire? [closed]
Suppose there are 2 nodes A and B in the above circuit. If A has 2 incoming currents $I_1$, $I_2$, and B has 1 incoming currents $I_3$, $I_4$, is it correct to write the equation of whole nodes and ...
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Circuit problem [closed]
Hello, can someone please help me on this problem?
Question: calculate the potentials at A and B.
The solution says that they are both 12V "due to symmetry" but I have no idea what is the ...
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Why is the current entering a conductor the same as the one exiting it?
Suppose I have a conductor connected to a battery. The current starts flowing through the conductor.
Why is the current entering the conductor the same as the current leaving the conductor?
Its ...
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How is the answer to this question $1/c$ seconds?
This is a question from the YouTube science content channel Veritasium. The below image shows the question.
The question is about when will the bulb begin to glow after the switch is turned on. The ...
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How long does it take for a battery to begin to produce a current after it is shorted? [duplicate]
From the moment you short a battery, how long before the current BEGINS to flow. Does a virtual photon need to travel the path of the wire? I was thinking it would be the length of the wire divided by ...
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A loop of wire with circumference of a lightyear is connecting a bulb and a battery. How long will the bulb take to light up?
Imagine a circular loop of conducting non wire with a perimeter of a light year. There is a powerful battery (able to produce a voltage that is higher than the drop in wire resistance) and a bulb ...
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Asking for proof for total voltage is equal to the sum of the voltages of the resistors (connected at series pattern) [closed]
Recently I was taught that when a set of resistors are connected as a series pattern the total voltage of the resistors is equal to the sum of the voltages of each resistor. I know how to prove this ...
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Why the Voltage across a capacitor equals that of the battery
This is how I look at capacitors. When the battery is connected electrons are pushed from the battery and accumulate on the capacitor, this occurs until the repulsive electric force equal that of the ...
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Inductor back emf
If I have that circuit, the equation that describe the circuit is: $\epsilon = L \frac{dI}{dt}$.
Now, if the back e.m.f. is equal to the source e.m.f, how current can pass? and it should pass because ...
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Physical laws limiting the size and energy density of battery/capacitor [closed]
The size and energy/power density of battery are always under active research and it would be nice to have small-sized battery with high energy density as well, but this seems to be nearly impossible.
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What is the relation between electromotive force and energy stored in a cell which can be converted to other energy in the external circuit?
We usually define electromotive force of a cell as the energy stored in the cell(atleast I have noticed it to be defined like that). But isn't electromotive force equivalent to electric potential ...
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Why is voltage used when measuring the strength of a battery and not electric field?
I'm not sure how to ask this but,
I started learning about electromagnetism with how charged particles behave in electric fields. This was easy and intuitive to understand. But I felt a disconnect ...
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Why does a drop in resistance lead to a drop in voltage?
I was working on this question which I know the answer to but I am still confused. I get that resistance is due to collisions on the atomic scale where the electrons' kinetic energy is transferred to ...
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Will the electron in a circuit without a load gain ever more potential energy every time it passes through a battery?
Say we have a circuit without any load, just a wire and a 1.5 V battery, so there is no full potential drop as it gets to opposite terminal. Will there be 1.5 V of potential added every time it passes ...
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British Physics Olympiad Round 1 2010 Q2a - Find potential difference between A and B [closed]
I've been trying some British Physics Olympiad past papers. In the 2010 Section 2 paper, the first question is the following:
I've never seen a circuit like this, and I'm unsure what the correct ...
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A circuit with 2 resistors in series - current in between them
Let us have this circuit:
We know from Kirchhoff's laws that the current I1 entering R1 and current I3 exiting R3 are the same, I1=I3.
But the point that bothers me is that: we know according to Ohm'...
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Why are potential drops concentrated at resistive elements?
I do not understand why potential differences in the electric field in a circuit are concentrated at resistors when the potential, to my knowledge, is purely dependent upon location in the field and ...
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