# Tagged Questions

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

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### Use of rheostat in a potentiometer practical?

in potentiometer practical why a rheostat is used in series to potentiometer wire? as we move the jokey the primary circuit current will also change. so is it to flow same amount of current by change ...
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### Why current in series circuit is the same?

I have read in the internet that the charges do not have any other path to go and they must go through the same in a series circuit,hence the current is same. It was quite convincing but what ...
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### Capacitor in AC circuit

Can someone explain to me the process of discharging of a capacitor when the EMF of AC source is decreasing? And where do charges go? I mean if there's a weak battery, it will be charged but what ...
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### If the potential drops across a resistor (=$V_d$) then shouldn't the potential difference be the $\epsilon-V_d$?

Consider the following circuit: Suppose a current $I$ travels in both the branches, then as the current $I$ passes through the $60$ ohm resistor, there will be a drop in the potential of $60I$. ...
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### Inductor potential difference direction

If you have increasing current going down an inductor, the inductor will produce a potential difference to produce a counter current in the opposite direction, or up. The lower potential is then on ...
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### Why is a circuit of linear elements itself linear?

A resistor's voltage is proportional to it's current. V=iR. And a source maintains a constant voltage or current. So these are linear, time independent relations. If I put combinations of them in a ...
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### Kirchhoff's laws in phasor domain

While analysing AC circuits, we write voltage, current etc all with complex numbers namely "phasors". While studying the same, I wondered if Kirchhoff's laws held good with current and voltage in ...
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### Is power still consumed when we switch off the lights?

I was having heated discussion with one of my friends. We were discussing Earth Hour and its role in saving electricity, and creating awareness. He stated that even if you turn off the lights, the ...
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### Finding Inductance in an AC RLC Circuit?

In the laboratory you find an inductor of unknown inductance $L$ and unknown internal resistance $R$. Using a dc ohmmeter, an ac voltmeter of high impedance, a 1 microfarad capacitor, and a 1000 Hz ...
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### What happens in the RC circuit when being charged?

Say I have this RC circuit and at the start, the switch is off (current going from left to right and the starting point is just above the battery). I understand that then the capacitor acts just like ...
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### With the help of a given charge is it possible to obtain a charge many times greater in magnitude

Consider a spherically conducting sphere. If a charge(say positive) is placed near the sphere, then it will lead to separation of charges inside the sphere.My question is, can we create charges more ...
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### Series circuit of capacitor and ohmic resistance: Voltage drop at Capacitor? [closed]

I have a question to an exercise I am currently trying to solve. It is given an Capacitor and an ohmic resistance in a series circuit. The whole voltage is 40V, the resistor has an resistance of 10kΩ....
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### Making a conductive paint out of graphite powder [closed]

I want to make a conductive paint out of graphite powder and gum to use as an electrode. What shall be the best gum to use, as i need a low resistance of around some kilo Ohms. I am getting very high ...
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### Which makes for a better equivalent capacitor? In series or in parrallel? [closed]

I understand how capacitors in series and in parallel work. However, I am wondering if it makes a difference, in terms of making a better capacitor that can store more charge, would you connect them ...
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### Imaginary component in capacitive reactance

This is a trivial question in first year but, unfortunately, this popped up in an elementary yet compulsory lab experiment. The capacitive reactance is defined as $$X_{c}=\frac{1}{\omega c}$$ The ...
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### Adding two same DC voltage source in parallel

In a parallel circuit(imagine two branches),with one DC voltage in a branch and another DC voltage in a branch, what is the method of computing the total DC voltage? The voltage through each component ...
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### Reducing voltage with resisitors [closed]

I am working on a project in structure, in which i have to rotate the second storey of my building, now my assembly consists of 12 v battery connected in parallel with 12v motor which is connected to ...
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### How does electricity travel through a set of resistors arranged parallel to each other? [duplicate]

For calculating net resistance in a combination of parallel resistors we use 1/R=1/r1+1/r2+1/r3....but electricity must travel through least resistance. Then how does this relation come in use? I am ...
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### Why is it said that electric current always flow from higher potential to lower potential?

Why is it said that electric current always flow from higher potential to lower potential? It is said that current flows from positive terminal to negative terminal, but it is actually the negative ...
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### Logarithm of the voltage of the inductor in RL circuit experiment is nonlinear with time

I performed an experiment about the RL circuit, with following circuit: (I used the PASCO RLC circuit lab.) By Kirchhoff's voltage law, (denoting the emf of the signal generator $\mathscr E$, ...
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### What is the current passing through wire AB as a function of angle theta? [closed]

This is a high school contest(CAP) question: Consider a circuit made of a wire with uniform resistance in a shape of a circle as shown in the picture. The circle is connected diagonally from point A ...
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### Resistance of a plate of smaller plates made up of different materials?

This problem propped in my head yesterday related to a project I'm working on and I just can't figure out how to crack it! If we have a large plate made up of nxn smaller plates, what is the ...
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### How can current remain same when potential difference decreases?

According to Ohm's law, $$\text{potential difference} = \text{resistance}\times\text{current}$$ Also, current remains the same everywhere. Now when current passes through a bulb, the electric ...
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### Is impedance the ratio of voltage to current at any instant?

My book defines impedance as the ratio between the amplitude of voltage to that of the current (Vmax to Imax), I just wanted to make sure whether its also true for the instantaneous values of voltage ...
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### Things that must be considered when mass producing a capacitor [closed]

The question is to list four things that must be considered when a capacitor is chosen for inclusion in a circuit which is to be mass produced. Are there a specific set of four things? I've come up ...
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### To determine the path of current in a complex circuit. (CAP contest question) [closed]

How to determine the path of current in this diagram ? Intuitively, I guess the current won't pass through wire DC... Any help will be appreciated!!!
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### Power dissipation in AC RC circuit [closed]

Can anyone help me with this question? A 20 A peak-to-peak 60 Hz current passes through a 0.01 µF capacitor which is in series with a 33 Ω resistor. What is the power dissipation? I have ...
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### Why electrons flow through a wire connected to a battery?

I would like to know why does electrons flow through a wire connected to a battery as said in AC/DC: What's the Difference?.It tells that "the electrons that are stripped from the carbon electrode is ...
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### Opposing currents in a Ciruit

If I have two currents flowing in opposite directions in a wire where both currents are equal magnitude and their is a bulb on the same wire does the bulb light up at all or is it bright/dim ?
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### Ohm's law deviation

In terms of superconductivities and diodes (I do not know anything else except these), Ohm's law deviate from a linear relation. I search many titles or tags for this but I did not understand properly ...
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### Why does this circuit work and the other doesn't? [closed]

if we connect the set up like this the bulb glows but if we connect the [right wire] to the [earth of the left] then the bulb [doesn't glow]. Why does that happen?
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### Why does adding more components in parallel increase the current?

Why does adding more components in parallel increase the current? Shouldn't the charges be more distributed, so they can't 'push' each other at the same rate anymore?
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### Movement of charges in presence of electric potential difference

This might appear to be a bad question to some but i can't figure out the answer. While reading about an electric circuit, i found this on the web: Over the course of time, one could think of ...
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### what is the analog of electronics for quarks or protons?

Is there an equivalent field for quarks or for protons as there is electronics for electrons where you can build engineer and mess around with things? May be even hack ?
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### Potential Dividers - Why do I need the second resistor?

So I am doing the OCR Physics GCSE course, and I have just learnt about potential dividers in electronic circuits. I get that the first resistor steps down the voltage so a component with a lower ...
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I think it is not dublicate question. Although there are many solution, I did not understand logical mean properly. my question is that in the below circuit, How can I find equivalent resistance? ...
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### explanation of the solution of equivalent resistance [duplicate]

I think it is not duplicate I wonder that explanation of the solution I searched and I found answer to my question.Although there are many solution, I did not understand logical mean properly. my ...
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### solution of the equivalent resitance [duplicate]

I searched and I found answer to my question.Although there are many solution, I did not understand logical mean properly. my question is that in the below circuit, How can I find equivalent ...
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### Potential Difference Across Components in Parallel & Series Circuits

So I have two questions, but they're kind of linked so I'm putting them in one. 1) I have a simple circuit with a battery connected to three lamps in series. If I then add a second battery but ...
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### What actually goes on in RLC circuit?

I already have difficulty understanding how each of the RLC circuit elements work individually as it is, and I have no idea how they work simultaneously in an RLC circuit. My schoolbook represents the ...
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### Why don't capacitor charging graphs look like other exponential growth graphs?

Sorry if this question is stupid, but I can't find any answers for this online. Physics websites show that capacitors charge and discharge exponentially. The discharging graphs of charge against time ...
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### Voltage in a circuit across a metal wire

I have a cell of e.m.f. 2.0V and negligible internal resistance, which is connected to a variable resistor R and a metal wire. The resistance of the metal wire is 3.4 Ohms. The resistance of the ...
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### Explaining why there is current in a circuit with a capacitor whilst the capacitor is charging

The question I'm trying to answer is part b) of the question below: My answer was: As some of the electrons will initially be repelled by the electric field of the negative plate, there will be ...
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### Capacitors in an AC circuit

Can I combine capacitors in the same way for an AC circuit as I can for a DC circuit (In series or in parallel)? Does the same apply for simplifying resistors?
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### Can current be induced in a grounded conductor?

I'm engaged in a rather lively debate with a group whose physics I believe to be a bit shaky. Basically they're claiming that if a conductive object is grounded to earth, the current cannot be ...
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### RC circuit energy [closed]

I am quite new at circuit analysis and I have a question about a RC circuit, with the resistor and the capacitor connected in series. I want to find the energy supplied by the ideal voltage source ...
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### In the Nernst equation $E=E_{cell}-\left(\frac{0.0592V}{n}\right)\log Q$, what does the $E_{cell}$ represent?

In the Nernst equation $$E=E_{Cell}-\left(\frac{0.0592V}{n}\right)\log Q$$ what does the $E_{cell}$ represent? I read that $E_{cell}$ is the standard state condition of the cell, let us say that we ...
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### How does a capacitor pass the flow?

Capacitor has just two conductor surfaces which have no touch. How can it pass the electric flow when there's no touch between the surfaces?