All Questions
10
questions
5
votes
2
answers
135
views
What is the "closed circuit" of a bug swatter racket?
There are bug swatter racket that can kill fruit flies, mosquitos, or flies, if the insect touches the metal mesh.
However, when I look at the construction of the device, the metal mesh is all one ...
- 151
0
votes
1
answer
68
views
Current flow with no resistance
Imagine a simple circuit consisting of a battery with potential $V$ connected to a resistor with resistance $R$ by a loop of copper wire with $0$ resistance. It is obvious that a current $I=\frac VR$ ...
- 366
9
votes
5
answers
4k
views
Why is it easier to raise AC current to high voltage than DC?
In my country (and maybe all around the world I don't know) once electricity has been generated, it is then raised to 200k Volts for transportation.
I know this is to reduce the loss. Given $P=U.I$ ...
- 201
2
votes
3
answers
147
views
Electricity supply in homes is AC but what about rms value that has only one direction? [closed]
In our homes, electricity supply is AC.but we have rms value in our homes...How do they relate? Is rms value generated in transformer or what??
- 21
2
votes
2
answers
47
views
Why do the two relations of Power in a resistive load $P= I^2 R$ and $P = V^2/R$ (Assume Ideal resistances ) seem contradicting in this situation?
I have seen similar questions in the forum but they fail to be very specific .
I would ask the question from the viewpoint of Problem Solving. Let me put this question from a textbook :
A heater coil ...
- 27
0
votes
3
answers
739
views
Why does the power remain constant during the stepping up and stepping down of current in transformers?
I understand quite a bit of transformers, their structure and other concepts and formulas related to mutual induction. However I'm not able to explain why the electrical power has to be constant ...
user248823
0
votes
1
answer
315
views
What causes changes in frequency in the Nation Grid electricity supply? [duplicate]
Following the power cuts in Britain this week, we were told that lack of power being generated led to a drop in the AC frequency as shown in this graph:
I understand why a stable frequency is ...
- 101
0
votes
2
answers
54
views
Current law explained
Kirchhoff's Current Law (KCL) is experimentally proven but what exactly happens?. I have made a model by taking the drude model and adding the interactions between the electrons and the reason why ...
- 49
-1
votes
1
answer
46
views
How computer knows how much charged battery is? [closed]
How does phones and laptops knows how much charged the battery is? I found lot's of simple devices like tv remote can also do that. Whats the mechanism behind that and does it vary with different ...
- 39
0
votes
1
answer
62
views
How come the current is not determined only by the first resistor it encounters?
I was reading about circuits on this link, where they use a tollbooth analogy to explain electricity. Now either this is a bad analogy or I am missing something, but let's consider a circuit that ...
- 139