All Questions
172
questions
2
votes
2
answers
610
views
Ohm's law and Joules heating
Ohm's law state that the ratio of V and I gives us a constant value of R provided that the temperature is kept constant throughout. However, in accordance with the joule's heating it would get heated ...
- 29
0
votes
1
answer
199
views
Why the potential at positive terminal is considered to be high?
even though it's the electrons that move from negative terminal of the battery and gets move along the external circuit and finally enters the positive terminal of the battery and due to battery force ...
- 29
0
votes
1
answer
80
views
How do charges away from the terminal react when the switch is flipped on?
Let us say we have a simple purely resistive DC circuit. When we flip the switch a current starts flowing which after some time becomes constant. Now, I know that the electric field across difference ...
- 405
1
vote
2
answers
303
views
When to use Ohm's law as opposed to using power formula?
I am a mechanic trying to gain a better understanding of electrical theory on vehicles. I have a sound understanding of Ohm's law and also the power formula (Power = Voltage x Current)
However, I am ...
- 15
8
votes
4
answers
2k
views
What's the point of an RMS value? [duplicate]
the RMS (root mean square) value of $f(x)$ is defined as:
$$f(x)_{rms}=\sqrt{\frac{\int^b_a (f(x))^2dx}{b-a}}$$
Why do we do this very specific thing of taking the square, the mean, and then the ...
- 167
3
votes
4
answers
4k
views
How much current will go through my body if I were to put my finger in an outlet?
i know this is a silly question, but i couldn't manage to wrap my head around it. I am kinda new to electronics.
My home's outlets provide 220V. Upon doing some (a lot) research, the current that ...
- 41
2
votes
1
answer
575
views
Power loss in power cable contradiction
To minimize the power loss in long-distance power cables it is best to minimize the current and maximize the voltage. This is because the power loss in the cable is calculated by $P=VI$, which we can ...
user260791
0
votes
2
answers
837
views
Energy Loss in Resistors [duplicate]
What kind energy of electrons is lost when current passes through a resistor?
OR
What happens to electrons when they pass through a resistor?
Does current decrease when its passes through a ...
0
votes
3
answers
11k
views
Why does increasing voltage increase current? [duplicate]
If we increase voltage, we are increasing energy per coulomb. How does it increase the number of coulombs per second (current)?
1
vote
2
answers
241
views
Why does the current stay same everywhere in a series circuit [duplicate]
Current in a series circuit are the same everywhere, but when there is a bulb creating a potential difference, wouldn't the rate of the same number of electrons flowing, coming out from the bulb ...
- 113
1
vote
1
answer
287
views
Is there a potential difference across the bulb after current passed through a diode?
I understand that voltage can exist without current so what I want to ask is will there be a potential difference across the bulb(situated after the diode) when a batteries supplied energy through a ...
- 113
-1
votes
3
answers
93
views
Current and voltage - Incompatibility between Ohm's Law and Power Law! [duplicate]
Ohm's Law: I $=\frac{V}{R}$: Increasing voltage increases current.
Power Law: P $={V}*{I}$: Increasing voltage decreases current.
Am I missing something?
- 340
5
votes
1
answer
655
views
How are electric and magnetic fields able to travel through space and wires, and how are they more than mathematical constructs?
Once I was taught that light is physically made up of in-phase E and B fields oscillating perpendicularly, it was a little baffling because I always thought fields were just analysis tools (or even ...
10
votes
3
answers
2k
views
Does an electric current flow in an open circuit?
When the positive and negative terminals of a battery is connected through a wire, an electric current flows across the circuit. Generally, electrons are the ones that flow (from negative terminal to ...
- 167
10
votes
9
answers
3k
views
How does the current remain the same in a circuit? [duplicate]
I understand when we say current, we mean charge (protons/electrons) passing past a point per second. And the charges have energy due to the e.m.f. of the power supply.
Now tell me, if a lamp has ...
- 340