All Questions
39
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Motion of a magnet inside a solenoid
I have a homework problem where a bar magnet is placed halfway inside a horizontal solenoid. A cut away shows that the magnet's north pole points to the left of the page and the south pole is outside ...
CommunityBot
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1
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194
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Self-inductance of a finite solenoid
Where did the $l$ in the denominator come from? I am talking about the $l$ in muNI/2l[...]?
I can't match LHS and RHS.
CommunityBot
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Current sensitivity in transformer scheme with SQUID
I've tried to determine the maximum current sensitivity in this transformer scheme but I'm not sure if my solution is valid. I need to find the relation between the current in the input transformer ...
- 207k
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1
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35
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What does "90 degrees ahead of phase" mean in inductance problems?
I've been working on this homework problem and I have determined that the induced EMF on the right coil is sin(x-90). However, I do not understand what "ahead of phase means." When I graph ...
- 207k
1
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0
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131
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Coilgun projectile force calculation
Please excuse me if I am completely wrong because I am a 9th grader but I hopefully am able to explain briefly about my problem. I was trying to create a function to calculate the Force of an iron ...
- 12.1k
1
vote
4
answers
408
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Electric Field in an Infinite Alternating Current Solenoid
Reading Wangsness's Magnetic Fields book I stumbled upon an explanation I can't understand. It goes like this: There's an alternating current solenoid with radius $a$. We know the magnetic induction ...
CommunityBot
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4
votes
1
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Why In the following $RL$ circuit, the connection to $b$ must actually be made an instant before the connection to $a$ Is broken? [duplicate]
In Resnick halliday, student 10th edition page - 795. In the topic current decay in RL circuit, the following statement is used, the connection to b must actually be made an instant before the ...
- 5,230
21
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4
answers
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Derivation of self-inductance of a long wire
Currently I am stuck, trying to derive the self-inductance of a long wire. According to literature it should be
$$L=\frac{\mu_r\mu_0l}{8\pi}$$
and in literature its derived by looking at the energy ...
2
votes
1
answer
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Find the inductance of the coil by potential difference of the circuit [closed]
A coil is connected in series with a 10.0 k$\Omega$ resistor. An ideal 50.0 V battery is applied across the two devices, and the current reaches a value of 2.00 mA after 5.00 ms. Find the inductance ...
- 5,230
3
votes
2
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246
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Using Faraday's law twice
I have trouble understanding Faraday's law when there is an induced current which in turn induces another current in the same circuit. I shall illustrate my confusion with an homework problem and I ...
- 39k
1
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1
answer
47
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Induced current in a rotating coil? [closed]
I'm a little bit confused with this problem: Find the induced current in a rotating coil with resistance R and inductance L. What I tried is this (assuming N=1):
$$\epsilon =-\frac{\text{d}\phi}{\text{...
- 1,614
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Induced voltage of a coil inside a coil
I have the length of the first coil, the number of turns in both, the current through the first coil and the cross-sectional area of the coil inside. I want to find the induced voltage. I know I ...
- 2,646
1
vote
2
answers
180
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Electromagnetic induction at the centre of a cylinder with rotating current [closed]
A long circular tube of length 10 m and radius 0.3 m carries a current I along its curved surface as shown. A wire-loop of resistance 0.005 ohm and of radius 0.1 m is placed inside the tube with its ...
- 452
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1
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201
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The self inductance of the motor of an electric fan is 10 H. In order to impart maximum powr of 50 Hz, it should be connected to a capacitance of [closed]
how can i solve this
(*)The self inductance of the motor of an electric fan is 10 H. In order to impart maximum powr of 50 Hz, it should be connected to a capacitance of
what is the concept behind ...
- 73.7k
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1
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Would the following 2 solenoids repel or attract each other? [closed]
Question:
Describe what will happen to two solenoids that are arranged next to each other as shown. The solenoids are the same length, and have the same number of turns and current flowing through ...
- 358k