Questions tagged [batteries]

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

Filter by
Sorted by
Tagged with
1 vote
2 answers
23 views

Why is lamp D off?

I understand the other lamps, but the answer for lamp d is that it is off as no current flows through it. I don't understand why? Please help.
user avatar
0 votes
0 answers
10 views

Good braking system for a mini car that can be triggered by a beam above the car that it will go past

I want to create a braking system for a mini car (essentially an aluminium body around 30cm long with 2 sets of axles with wheels (laser cut circles) connected to the end of each axle on the front and ...
user avatar
  • 1
2 votes
2 answers
73 views

EMF being equal through KVL

In the given figure,we connect three cells of different emf which are $V_1,V_2,V_3$ with a resistance $R$ in the first loop. Now suppose we emit current $I$ from $V_1$. $I$ gets divided into $I_1$ and ...
user avatar
  • 569
3 votes
1 answer
58 views

Using the sky and ground as a battery

Since there is a voltage difference between the ground and sky, shouldn't I theoretically be able to light a bulb by connecting one terminal to the ground and raising the other one to the sky (via a ...
user avatar
0 votes
2 answers
70 views

How is there current if there's no voltage?

Hi, I was trying to solve this problem, it asks to find the reading of ammeter. I think it has no resistance here. Does it mean that there's no potential difference, no voltage across ammeter? But how ...
user avatar
  • 13
0 votes
1 answer
38 views

Current flowing from lower to higher potential

In the above circuit, two cells are connected in series to an external resistance $R$. Now the current going from point $A$ must return back to point $B$ of the cell. But for that it has to pass ...
user avatar
  • 569
0 votes
0 answers
35 views

Working principle of the five(5) needle telegraph by Cooke and WheatStone

So I’m studying the history of telecommunications and came across the five (5) needle telegraph by Cooke and WheatStone. I want to replicate it but can’t get a grasp on the working principles. In a ...
user avatar
0 votes
1 answer
71 views

Is the positive terminal of a Daniell cell positively charged electrostatically?

Suppose, the circuit is open. I understood from @Dale's answer that the negative terminal of the battery is indeed electrostatically negatively charged. Suppose, it can have a charge of $-0.5C$. ...
user avatar
0 votes
0 answers
11 views

What happens to the electric potential if the amount of positive charge is greater than the amount of negative charge or vice versa?

In a Lithium-ion battery, the lithium ions are stored in the graphite layer while the electrons remain behind the electrolyte when the battery is fully charged. What if more lithium ions enter the ...
user avatar
3 votes
1 answer
50 views

What's the highest theoretical energy density in a chemical battery?

Is there a theoretical limit to how energy dense chemical batteries can be? How can one calculate them? And what stops us from reaching those limits?
user avatar
  • 55
0 votes
2 answers
73 views

When two capacitors are connected in parallel, do they drain battery quicker?

My question is actually my answer to a question I asked myself i.e 'how does potential difference remain same for both capacitors which are connected in parallel, and not get distributed' When 2 ...
user avatar
1 vote
0 answers
29 views

How does 'symmetry' of a circuit allow us to find currents when a junction splits into 2 different resistors?

The book says what the picture shows. There's no parallel or series resistors and I could solve it with 4 different currents (if the top blue arrow is i3 and bottom green is i4) but that's a 4 ...
user avatar
-1 votes
2 answers
30 views

If a battery (cell) was elongated, will it have higher voltage?

Voltage is the potential difference between the terminals of the battery,and this potential difference is created by the work that the chemicals inside the battery had done. Also, work done is ...
user avatar
1 vote
1 answer
34 views

Circuit with internal resistance [closed]

A circuit is formed by connecting a resistor between the terminals of a battery of electromotive force (emf) 6 V. The battery has internal resistance. Which statement is correct when 1 C of charge ...
user avatar
  • 31
1 vote
3 answers
47 views

Difference between 2 points a circuit [closed]

I am asked to find the voltage difference between points A and B, namely $V_a - V_b$ of the following circuit: I don't exactly know how to approach this however. Is it as simple as going counter ...
user avatar
0 votes
0 answers
22 views

Heat dissipated in a capacitor network on switching a key

Suppose we have this capacitor network connected to a battery($V$) with the switch initially open. On closing the switch whilst keeping the battery connected, we find that some heat is dissipated. We ...
user avatar
1 vote
2 answers
50 views

Would "Energy Vault" gravity battery work in water?

To be more specific, will one block lowered into water release the same amount of energy as in air?
user avatar
0 votes
1 answer
29 views

Terminal voltage derivation

How can I prove the following? $\ V_{ab}=\mathcal E-\ Ir$. Here $\ V_{ab} $ is terminal voltage.
user avatar
0 votes
1 answer
59 views

Voltage drop across a circuit misunderstanding

Consider a circuit with a 20 volt battery and a resistor (no other components). Next, let's say I choose a point A on the positive terminal of the battery. The current flows from point A, around the ...
user avatar
-1 votes
5 answers
74 views

How is there a potential difference when there is no voltage drop in a simple single battery circuit?

Suppose we had a simple circuit where one end of a copper wire was connected to the negative terminal and the other end was connected to the positive terminal. If there is no voltage drop between any ...
user avatar
-1 votes
1 answer
24 views

Battery efficiency [closed]

I have 4000 mah 4 cell and a 5000 mah 3 cell Which battery is more efficient. Higher mah or more number of cell. I am selecting batteries for rc plane
user avatar
0 votes
2 answers
56 views

How does a cell discharge their voltage?

I'm posting this question because I haven't been able to find any sources on the internet to make sense of. The statement I am working with is as follows: The terminal potential difference of a ...
user avatar
  • 157
0 votes
2 answers
71 views

Is battery a source of electrons OR a driving force?

A more elaborate question " With my previous knowledge I am aware that a wire possesses a sea of electrons ( free electrons) and the flow of those electrons is called current . The energy to flow ...
user avatar
0 votes
1 answer
57 views

Electric Potential in a Circuit [duplicate]

In physics class my teacher is indicating that the electric potential in a wire remains constant until a resistor occurs. If the electrons in the wire are moving away from the negative terminal of the ...
user avatar
4 votes
2 answers
163 views

How does electrical energy in parallel work out?how does less energy travel through more resistance

Before asking my question,I want to talk about certain points 1.Lets suppose there is a battery of 12 volts,this means that the potential difference between the negative and positive terminal of the ...
user avatar
1 vote
3 answers
110 views

Why am I getting negative current on the right loop of the Kirchhoff's circuit?

I have the above circuit and I calculated that the: left loop = I1(Rc+4) - I2(Rc)=12 right loop = I1(Rc) - I2(Rc+3) = 5 I then generated numbers from 0 to 5 ohms with stepsize 0.1. After replacing ...
user avatar
  • 13
1 vote
3 answers
105 views

Where do electrons flow inside a battery? What happens inside a battery?

Sorry, if this sounds silly, but I have had this doubt from a long time. Please help me, I'll forever be grateful to you. I'm a student of 10th grade. This is my doubt: What happens when electrons ...
user avatar
0 votes
1 answer
26 views

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?
user avatar
0 votes
1 answer
53 views

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, ...
user avatar
0 votes
1 answer
39 views

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'...
user avatar
  • 1
0 votes
0 answers
18 views

Parallel, planar electromagnet circuit

Given an array of parallel conductors - all with mutual inductance - can Ampere's Law be roughly applied to the center region as well? Here is a visual: Idealized Ampere's Law to motivate the ...
user avatar
  • 101
0 votes
1 answer
36 views

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 = ...
user avatar
  • 285
0 votes
2 answers
49 views

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 ...
user avatar
  • 558
2 votes
3 answers
354 views

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 ...
user avatar
  • 81
0 votes
2 answers
52 views

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 ...
user avatar
  • 81
14 votes
4 answers
1k views

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 ...
user avatar
  • 1,379
0 votes
2 answers
52 views

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 ...
user avatar
  • 195
0 votes
1 answer
42 views

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 ...
user avatar
13 votes
5 answers
986 views

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 ...
user avatar
  • 233
-1 votes
5 answers
147 views

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 ...
user avatar
-1 votes
1 answer
31 views

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 ...
user avatar
0 votes
1 answer
79 views

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 $...
user avatar
  • 101
0 votes
2 answers
46 views

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 ...
user avatar
4 votes
2 answers
112 views

What sort of field does a battery create inside a wire or anything at all in general?

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 ...
user avatar
  • 424
2 votes
1 answer
125 views

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 ...
user avatar
0 votes
4 answers
173 views

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? ...
user avatar
  • 441
2 votes
1 answer
101 views

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 ...
user avatar
0 votes
1 answer
73 views

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 ...
user avatar
  • 424
0 votes
3 answers
84 views

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 ...
user avatar
0 votes
0 answers
19 views

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 ...
user avatar

1
2 3 4 5
16