All Questions
15
questions with no upvoted or accepted answers
1
vote
2
answers
259
views
Does a higher voltage always mean a higher electric field strength?
In a step-up transformer, the output voltage is higher than the input voltage, while the output current is lower than the input current. Basically, since P = VI is conserved, the current has to ...
- 337
1
vote
2
answers
147
views
On a nanoscopic level, what really happens to the electrons in the secondary coil of a step-up transformer?
I know that when AC is passed through the primary coil of a step-up transformer a higher emf is induced in the secondary coil (with more turns) of the transformer. Since energy is conserved, and P = ...
- 337
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
vote
0
answers
159
views
Electrical resistivity calculation of a cylindrical material
I have a copper rod, its diameter is 13mm, and its height is 13mm. I want to check its electrical resistivity. I have tools to give this copper a constant current by two points (the two black dots in ...
- 111
0
votes
3
answers
102
views
Potential drop against internal resistance of cells in combination
Suppose two cells of emf and internal resistance e1, r1 and e2, r2 respectively are connected in series. The negative electrode of 1st cell is connected to negative electrode of the second cell. Why ...
- 1
0
votes
1
answer
47
views
Does $\frac{V}I = k$ necessarily imply that the wire follows Ohm's Law?
Does $\frac{V}I = k$ necessarily imply that the wire follows Ohm's Law?
https://i.sstatic.net/ClEqP.jpg
Say, for a range of about 15 Volts, I get a good $\frac{V}I = k$ result, after which the ratio ...
- 101
0
votes
2
answers
76
views
Electrical vs Heating Insulation
Let's say we have a 120V cable and a 600V cable, this means that the 600V needs more electrical insulation to prevent the insulator from exceeding its dielectric strength. But in the other case, the ...
user215726
0
votes
1
answer
105
views
How do I keep the peak voltage in a coil connected to a signal generator constant, given that I'm changing the frequency?
I want to vary the frequency of the A.C supply, and hence change the peak current in the circuit. But V=IR, so won't the peak voltage also be changed if I change the peak current?
- 254
0
votes
0
answers
52
views
What happens if an electrical current has two paths of unequal length?
Suppose I connect one 1 km cable and one 1000 km cable to the same pole of a power source and also connect them together at the other end. Suppose (theoretically) the longer cable has the exact same ...
- 101
0
votes
0
answers
130
views
Is it possible to raise the voltage of a power source by lowering its current indefinitely (i.e. transformers)?
Let's say you have a D battery. You wire it up to the primary of a step-up transformer, which you then in turn wire up to another step-up transformer,...etc. Is there a limit to how high the voltage ...
- 1,958
0
votes
2
answers
39
views
Determine the size of a conductive medium
Are there any measurable characteristics that would allow one to discern the size of a conductive medium?
Say I apply the same voltage to a two foot long wire and a four foot long wire. Is there ...
- 11
0
votes
3
answers
138
views
How does the initial turn-on transient decay into the steady state in a given circuit?
How does the initial turn-on transient decay into the steady state in a given circuit? For example, in a parallel circuit, how does the voltage over both arms of the parallel circuit equal to that of ...
- 1,235
0
votes
1
answer
790
views
Why does no current flow in a smartphone charger when it's plugged into a socket, but no phone is connected?
According to the fact that a phone charger consists of a transfomer and a recitifier, there should - still - be a difference in potentials, even though no phone is attached to the charger.
- 231
-1
votes
1
answer
144
views
The flow of electric current
If positive charges have higher electric potential difference than negative charges then why the negative charges (electrons) are the one that are moving in a circuit? and to my knowledge the ...
- 1
-1
votes
1
answer
399
views
Not enough current to supply load
Are there cases where a power supply can offer xV, which is required by a device, but be unable to supply enough current?
For example, a voltage divider not only lowers voltage, but limits the ...
- 119