All Questions
Tagged with electric-circuits work
33
questions
9
votes
10
answers
6k
views
Why is Power = Voltage $\times$ Current?
So P = I*V because V is the amount of energy per coulomb and I is the amount of electrons going past a cross sectional area in one second.
So if we do the math, since V = J/C and I = C/sec, if we ...
- 191
9
votes
4
answers
5k
views
Work done by magnetic field on current carrying conductor
Suppose a wire of length L carrying a current I is kept in a uniform magnetic field B perpendicular to the current. The force on the wire will be IBL and work done by magnetic force when wire moves a ...
- 303
4
votes
1
answer
14k
views
What is the work done by battery and what does work done on battery mean?
Suppose we have a charged capacitor connected to a battery. Now we push the plates of the capacitor away from each other decreasing capacitance and hence energy stored in the capacitor decreases. Now ...
- 239
4
votes
2
answers
1k
views
What exactly is “electrical energy”?
If the two fundamental types of energy are kinetic and potential energy, is electrical energy simply the kinetic energy of charge carriers?
Also, is the statement “A cell converts chemical potential ...
- 1,546
3
votes
4
answers
379
views
Voltage as work in electric field and in Ohm's law
I am struggling to reconcile the definition of voltage as work done moving a unit of electric charge between two points in an electric field and voltage in Ohm's law.
In the work definition, ...
- 155
3
votes
3
answers
7k
views
What does electric potential mean in a circuit?
As we know that electric potential at a point is defined as a work done by me to carry unit charge from infinity to that point. How can I use this definition in an electric circuit that contains a ...
- 49
3
votes
2
answers
1k
views
How do voltmeters measure work done over a component?
In my physics class, we were shown the picture below to measure the current and potential difference through a component. We were told that the resistance of the ammeter is as low as possible, and the ...
- 145
2
votes
5
answers
611
views
Can we use work equation to derive Ohm's law?
Ohm's law states:
$$\textbf V=\textbf I\cdot\text R$$
where $\textbf V$ is voltage, the electric potential difference from a point to another (Electric potential is the potential energy of a positive ...
- 219
2
votes
2
answers
505
views
Sign of work done in an $L$-$R$ circuit
Suppose we have a L-R circuit with an inductor of inductance $L$ and resistance $R$ and emf $\epsilon$. Now initially when the switch is closed no current is present. Let the maximum current be $I_{...
- 159
2
votes
1
answer
164
views
Does a CPU do work?
This question is simple to the Core (excuse the pun).
CPU = Central Processing Unit (for computing)
Lots of people including myself say "My CPU is doing a lot of work."
But I do not think ...
- 121
2
votes
3
answers
392
views
Electric potential in circuits
From what I understand from my notes, an e.m.f or electromotive force provided by a battery is the electrical energy per unit charge converted from other forms of energy required to drive a unit ...
- 79
1
vote
3
answers
2k
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When talking about potential difference in a circuit, whose work done are we talking about?
I'm asking this because it seems to me that when we talk about PD around a charge (i.e. potential difference between infinity and a point), we're talking about the work done per unit charge by an ...
- 797
1
vote
2
answers
117
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Working of battery in circuit
The battery has a potential difference. So, shouldn't battery generate an electric field directing from the positive side to the negative side? If that's the case, we know that potential in a wire(...
- 1,179
1
vote
3
answers
5k
views
Why doesn't potential difference across circuit increase when length of wire increases?
Since $V=Ed$, why doesn't the electric potential increase when length of the wire increases. $d$ increases right? Is it because the battery only pushes the electrons from one terminal to the other and ...
- 295
1
vote
2
answers
256
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Work-energy theorem giving no work done on capacitor and dielectric when dielectric removed from capacitor [closed]
For this problem,
Do you please know why when considering that the capacitor and dielectric is our system, the work energy theorem gives the wrong sign for the change in electrostatic potential ...
- 49