All Questions
Tagged with electricity electric-current
791
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Why doesn't coil in an Ac generator not get deflected in accordance to the flemming's left hand rule when current starts to flow through it [closed]
Why doesn't coil in an Ac generator not get deflected in accordance to the Flemming's left hand rule when current starts to flow through it.
When the coil is ...
0
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1
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26
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Do attracted to electrode charged particles make current?
Consider a bulb with an anode. Cathode, is out of bulb.
Bulb is filled with gas.
Now, gas molecules are ionized by, for example external radiation.
Bulb should now contain "free" electrons, ...
- 361
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36
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Current in a Nonuniform Diameter Wire
According to the text Current depends on Area, but then in problems with a "nonuniform diameter" we say that the Current does not change even though the Area changes.
I think I understand ...
1
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1
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146
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How do electric fields in circuits exactly work?
I have been introduced to circuits and told that an electric field, along with a emf provided by an external source (which can't be electrostatic), causes electrons to move. They follow the direction ...
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0
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Resistance across different terminals of a material of variable resistivity [closed]
I have seen many questions in my book trying to find Resistance across different materials of variable resistivity(by integration).
For example, consider the following :
I can find resistance across ...
- 265
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2
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89
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Current returning to wire when passed through earth
Consider the following circuit:
I have a bulb connected to a battery and then the wire as shown is earthed from two points. Now, since across the bulb potential difference will be zero, no current ...
- 265
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1
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87
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Hysteresis phenomenon on a tungsten filament
I have a lamp with a standard filament bulb. A dimmer allows to modulate its intensity. It's an old low-end dimmer, so I assume it's a potentiometer that regulates the current in the bulb.
When I vary ...
- 101
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Does current make the full return trip?
In an AC system, the neutral wire is said to provide a return path for the current back to it's source. Given that the current is said to be alternating back and forth, how does this work, does the ...
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When using a screwdriver tester i am completing the circuit with 110v?
if i use a screwdriver tester, i am part of the circuit with 110v passing my body? isn't this dangerous?
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"Why do power lines use high voltage?" Loss in power equal to Current*Voltage? [duplicate]
I define P is the average power. So $P=IV$ and $I=\frac{P}{V}$.
$P_{loss}$ I define to be the power loss, which is equal to $I^2R$.
Substituting for $I$, $P_{loss} = \frac {P^2R}{V^2}$
So I get that ...
- 93
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How large a current is realistic for a mains wire? [closed]
I recently encountered this elementary physics question:
A mains wire outside your house is $15m$ above the ground. The power company says the voltage is $10 kV$, and the wire delivers $18 MW$ of ...
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4
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84
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About electric field and electric potential
We know that electric potential is the negative of work done by electric field in moving a unit charge from infinity to that place.
This statement shows that electric field causes a potential ...
- 105
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2
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32
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Will a circuit be closed if we make a 100% efficient LED?
Suppose we make a LED that is 100% efficient, that is, it converts 100% of electric current we supply to light. Based on my understanding of electric current, as there is no current flowing back to ...
- 419
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71
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Is drift velocity directly or inversely proportional to the length of the conductor?
One way that drift velocity can be represented is: $$v_d = \frac lt$$
$$\Rightarrow v_d \propto l$$
However, another way it can also be represented is:
$$\begin{eqnarray*}
v_d &=& \frac {I}{...
- 419
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3
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141
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What exactly is electric current?
In my textbook, Current is defined as the rate at which charge flows through a given surface (cross sectional area). These are my questions:
How can there be current through a given cross sectional ...
