An electronic system, with closed loop current flow, and relative electrical potentials present across electrical components.

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9
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6answers
901 views

Why is current the same in a series circuit?

So I am a 10th grade student and my teacher told me that the current is the same at every point in a series circuit. It does split up in parallel circuit but it then recombines and the current flowing ...
4
votes
3answers
5k views

Why is there no current flow when i connect two opposite terminals of two separate batteries

I don't understand this..maybe there is something wrong with my understanding of battery or electricity. I am learning about electricity more deeply this time. So please spare with me... So lets ...
1
vote
2answers
169 views

Why does a battery die more quickly when more resistors are added to the circuit?

I will be explaining what I think: A battery acts like a pump which provides energy to do work on negative charges to move them towards the negative terminal, and hence creating an electric field. ...
1
vote
1answer
70 views

Charge of electron in AC/DC circuit

If electrons in a DC circuit going through a metal wire carry only negative charge from negative to positive, then in a AC circuit through a wire does a electron carry both a negative charge and ...
-1
votes
2answers
832 views

what is the proper way to connect two light bulbs in a circuit? in series or parallel?

What is the proper way to connect two light bulbs in a circuit? in series or in parallel and why? My thought is that it's better to hook them in parallel, since if we take into account Ohm's Law, the ...
1
vote
2answers
255 views

Calculation of RMS current in half wave rectifier

While calculating RMS current in half wave rectifier, why we will consider only half wave that means only we consider the limits 0 to pi. But here RMS current is for AC input..so why don't we consider ...
7
votes
7answers
590 views

Why is the resistance in a parallel circuit smaller than the resistance in a series circuit?

So I was told in the physics class that the resistance in a parallel circuit is smaller than the resistance in a series circuit. Why does that happen? Is this statement also true for circuits which ...
0
votes
1answer
26 views

Question regarding Kirchoff's loop rule

My problem is that there are n cells connected in parallel which are connected to an external resistor. Now can we use Kirchoff's loop rule to evaluate the current through the resistor by considering ...
0
votes
1answer
128 views

How is a variable potential divider able to reduce current/voltage through a component to zero, unlike a variable resistor?

For example, the diagram in my text book shows a filament lamp, in series with a uniform resistive wire, which can have its voltage and current varied by moving the sliding contact, e.g., a ...
0
votes
1answer
104 views

How is a potential divider able to reduce current to zero?

For example, a filament lamp, in series with a uniform resistive wire, can have its voltage varied by moving the sliding contact, e.g., a rotatable wheel. However, why is a potential divider able to ...
1
vote
3answers
116 views

How to detect if resistors are in parallel or series?

Some circuits are easier to see which resistors are in parallel or series. However, when faced with a more complex circuit, I can't figure out which ones are in series or parallel. I am currently ...
5
votes
2answers
261 views

What is the area in Faraday's law if we have only a piece of metal moving in a magnetic field?

If a piece of metal of length $l$ is moving with a speed $v$ in a region where there is a uniform magnetic field $B$ perpendicular to it, there will be a potential difference across its terminals ...
1
vote
0answers
12 views

frequency passage inside AC ciruit

I've been checking YouTube about AC circuit lesson and been hearing about inductor passing low frequency and capacitor passing high frequency from alternating current and what does that mean by ...
2
votes
2answers
554 views

Why the EMF of a battery doesn't depend on distance between the two electrodes?

I have read that resistance of a conductor is directly proportional to its length. So, the EMF of a conductor (electrolyte of battery) should increase with increase in length/distance between the ...
0
votes
0answers
19 views

How do I calculate the effective resistance in this circuit? [closed]

How do I calculate the equivalent resistance across A and B when i) All resistors have a resistance in the given circuit of $~\mathrm{R }$? ii) The resistors in the given circuit have values as ...
1
vote
1answer
16 views

Range of voltmeter [closed]

I have understood how the range of an ammeter cannot be decreased. But I don't seem to understand how the range of a voltmeter can be decreased. Pls help.
0
votes
1answer
108 views

Discharging capacitor

When the capacitor is fully charged and the switch as it B, how can we apply KVL at that loop to reduce the equation to (-IR)? Why is it negative? At time = 0 is the current not zero? And it will move ...
0
votes
1answer
32 views

Same current flowing [closed]

In the following circuit how can we say that the current flowing through both the $4\Omega$ would be same . I know it would be same if in middle the $\frac{2}{3}\Omega$ is not there but here it is ...
-3
votes
3answers
75 views

Infinite staircase where each step is a 1 ohm resistor [closed]

There is an infinite staircase where each step is a 1 ohm resistor. How do you calculate the equivalent resistance between any of the two points on the staircase?
0
votes
2answers
242 views

Current on both sides of a capacitor

When a capacitor is connected to a DC circuit, what ensures that the current on both sides of the capacitor is the same? When charges arrive at one end of the capacitor they stop moving; presumably ...
0
votes
2answers
152 views

Closing a switch in series with a capacitor

Suppose we have the following circuit: Such that for $t<0$ the switch M was open. If we close the switch at $t=0$ what will the voltage on the capacitor, $V_C$, be at $t=0^+$? What about $\dot ...
0
votes
1answer
40 views

Circuit with voltage source, resistance and current source

Suppose I have a (closed) circuit with a voltage source $V$, a resistance $R$ and a current source $I$ (in this order). Is it true that the voltage across the current source is $V-RI$ ?
1
vote
2answers
64 views

Electrical equivalent of inverted pendulum

Background I am working on a summer project to design labs for undergraduate students. One of the topics is feedback and there is already quite a lot of stuff about passive feedback, so we might add ...
5
votes
1answer
12k views

Sign conventions for voltage drop and gain in circuit

In Sears and Zemansky's University Physics book and in many other books in English they define the following sign conventions (used for Kirchhoff loop rule for example): While in many other books (...
0
votes
1answer
45 views

Is it true that in a superconductor the current will always flow without a any electric source? [closed]

It came to my mind that when a superconductor is taken and a wire is joined to it to make it a complete circuit, the current is flowing through it. Now, I am removing the battery and joining the two ...
0
votes
1answer
30 views

Energy dissipation in current flow

In section 4.8, Energy dissipation in current flow, of Purcell and Morin's Electricity in Magnetism, the expression for the power expended by a resistor is derived. The sections includes the following ...
-1
votes
0answers
16 views

Relaxation Time in RC Circuits with a Metal Conductor

In section 4.8, Variable Currents and Capacitors, of Purcell and Morin's Electricity in Magnetism, the following is discussed: For a metal with resistivity typically $10^{−7}$ ohm-meter, the time ...
2
votes
5answers
39k views

Why does voltage remains same over Parallel Circuit

Why does voltage remains same over parallel circuit. If a resistor is connected in the circuit some of the charge should be transformed into heat and make a lack of charge after the resistor (in my ...
-1
votes
1answer
103 views

What is the voltage drop across a wire [closed]

If we attach a resistor in series, most diagrams only consider the voltage drop across the resistors. What happens when we remove all of the resistors? Why does the voltage drop across the wire become ...
1
vote
3answers
172 views

How does voltage divided by EMF show efficiency?

I get that electromotoric force (emf) is energy per coulomb supplied and that voltage is energy per coulomb used but I don't get what it means when we say that the voltage divided by the emf gives the ...
0
votes
3answers
213 views

What's the max speed a man-made satellite can travel in space before its circuitry stopped working?

Assume it could withstand extreme temperatures in either direction. I'm mainly curious what would happen to its circuits as it approached the speed of light.
3
votes
0answers
65 views

Can the Hall effect drive a current?

In the Hall Effect current is passed through a wide strip of metal in a perpendicular magnetic field. Since (some of) the negative charges in the metal move but the positive ones stay put, the ...
1
vote
1answer
126 views

Flux linkage of 2 coils in series

I have a question from magnetic circuits. I am an engineering student, therefore I will neglect some minor errors. There is a simple magnetic circuit with 2 coils ($C_1$ & $C_2$), with $N_1$ &...
1
vote
1answer
55 views

Equivalent Resistance between 2 points

Actually , I'm having trouble in solving for the net resistance of the below network of resistors. Can anyone help me finding the equivalent resistance between points a & b. My answer is $2/3r$...
2
votes
1answer
147 views

How do the different types of energy apply to voltage in a circuit

I was just wondering what happens in a circuit in terms of different types of energy transformations. If you apply a voltage to a circuit then electrons start moving (very slowly). Since the electrons ...
0
votes
3answers
82 views

Why fuse needs to be slightly more able to bear current than the appliance?

if I have a bulb with rated current of $4 A$ then why I need to connect an $5A$ fuse?( which has slightly more ability to bear current.)
2
votes
3answers
194 views

Can pulsating DC current be transformed?

Since pulsating DC current is changing, why doesn't it induce a changing magnetic flux in the transformer core? Is it able to induce a transformed current in the secondary coil?
6
votes
5answers
15k views

Potential difference (PD) and electromotive force (EMF) in terms of electrons?

I am trying to understand potential difference and electromotive force in terms of electrons. In the above 3 circuit diagrams the red shows (what I think to be) the distribution of electrons around ...
0
votes
1answer
432 views

Voltage across an inductor contradicts Lenz's law?

Imagine a simple circuit consisting of an alternating current source connected to an inductor. Assume they are connected in the following fashion: AC source - terminal A - Inductor - terminal B - AC ...
1
vote
3answers
696 views

Theoretical uncertainty of a circuit's total resistance when made entirely of resistors

My question in short(ish) is: Will the fractional uncertainty of a circuit made entirely of resistors with equal fractional uncertainties be the same as the fractional uncertainty of those resistors. ...
-4
votes
1answer
43 views

Determining if two resistors are in series or in parallel. [duplicate]

I know that this is a rather trivial question, but I've been having issues developing a problem-solving strategy for figuring out whether resistors are in parallel or in series. The Specific problem ...
-3
votes
2answers
42 views

Why would a series of cells not be suitable for a car battery? [closed]

A car battery needs to supply a current of $200A$ to turn over the starter motor. Explain why a battery made of a series of cells would not be suitable for a car battery. My thinking: I'm thinking ...
0
votes
1answer
42 views

Electric potential in a wire

I am slightly confused on the physics of direct electric circuits. Here is what I have been taught: Batteries (sources of emf) provide a constant potential difference between its terminals; ...
0
votes
1answer
167 views

Internal Resistor in a Diode

When we talk about the resistance of a diode (of the P and N region), is this resistance like the one inside an Electro-Motive Force or it acts like a normal resistor (external electric field exist)? ...
4
votes
7answers
61k views

Why the bulb glows brighter?

If the total current is divided into the branches in a parallel configuration and it is constant in series. How come the bulbs glow brighter when connected in parallel than when connected in series?
-1
votes
0answers
19 views

Which AC bridge circuits are oscillators? [migrated]

There are different types of AC bridge circuits like the Wheatstone bridge, Maxwell, Hay, Shering and Wien. I need to know which ones are oscillators but I still don't get the main reason why the ...
0
votes
1answer
80 views

Work done by the battery in series with capacitor with changing dielectric

If we have a battery with voltage $V$ connected in series with a parallel-plate capacitor of capacitance $C$ with dielectric $\epsilon$,and then we pull the dielectric out, the infinitesimal work done ...
1
vote
1answer
63 views

Differential equation in RL-circuit

I am self-studying electromagnetism right now (by reading University Physics 13th edition) and for some reason I always want to understand things in a crystalclear way and in depth. Now look at this ...
0
votes
1answer
108 views

What does “Receptor” convention refers to in RC circuits?

my question is How can we choose the convention in a circuit and what does it refer to ? Especially for a Capacitor I hear the terms "passive sign convention..." "receptor convention ..." "generator ...
0
votes
3answers
3k views

How is a potential difference created between two points?

I would like to know how potential difference is created between two points?Is potential difference created by adding more electrons at one side?If that's the case how to add more electrons at one ...