All Questions
39
questions
0
votes
2
answers
146
views
Conducting loops attracting each other
The problem is the following
Two identical, perfectly conducting loops are far apart and share the same axis. Each has self-inductance $L$ and a current $I$ flowing in the same direction, so the ...
- 1,161
2
votes
0
answers
1k
views
Finding the voltage across an inductor when opening the switch [closed]
Well, I've the following circuit:
In the circuit I want to find the voltage $\text{V}_{\text{Y}_1}\left(t\right)$ as a function of time, after I open the switch (this switch was closed 'forever' ...
- 21
1
vote
2
answers
137
views
Current in the inductor at $t=0$
$L_1 = 5H, L_2=0.2H, M=0.5H, R_0=10 Ω$, and $i_g=e^{-10t}-10 A$. I need to find $i_2$.
I've started with DE
$$i_2R_0+L_2(di_2/dt)+M(di_g/dt)=0$$
and solved it for $i_2$, so $$i_2=0.625e^{-10t}+Ce^{-...
- 111
2
votes
0
answers
118
views
Magnetic field due to a double tape line
I have been asked to calculate the inductance of a double tape line :
Now we know that $$ N\phi = LI$$
So let's calculate the magnetic field by assuming an amperian loop like this:
$$\int B.dl = ...
- 361
1
vote
2
answers
808
views
Is induced EMF proportional to the square of the number of turns of a solenoid?
In order for this question to be clear I must first give some context:
Consider a 10cm long solenoid (solenoid A) of radius approximately 1cm with 400 turns.
Let the current in $A$, $I_A$, change ...
- 2,470
1
vote
1
answer
357
views
Potential difference across the strips of an inductor [closed]
The voltage across the ends of an inductor is $L (di/dt)$. Applying the loop law $V = L(di/dt)$, so the voltage across the strips at a distance x measured from the "LEFT END" should be $V \frac xl$ ...
- 361
0
votes
2
answers
23
views
Magnetic energy in coil at time $t$ after circuit being hooked up
"A coil with inductance L = 50 mH and R = 600 ohm is coupled in series with a resistance R = 200 ohm to a battery with the voltage 12 V. How great is the magnetic energy in the coil at the time t = ...
user180617
1
vote
2
answers
3k
views
Magnet falling through a coil that does not form a circuit. Am I wrong or is the mark scheme?
So either this past paper is wrong or my ideas about induction have a problem.
The old exam I am doing asks what happens when you drop a magnet through a coil connected to an Amperemeter, and then ...
- 175
0
votes
1
answer
1k
views
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 ...
- 173
1
vote
4
answers
408
views
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 ...
0
votes
1
answer
107
views
Will there be any current induced in a purely capacitive circuit?
Will current be induced in a purely capacitive circuit if a magnetic field B is present perpendicular to it and a movable conducting wire completing the circuit is moving with a velocity v.
Just want ...
1
vote
1
answer
132
views
How to simplify the maths to determine the mutual inductance between two multi-layer rectangular coils of arbitrary dimensions?
I am experimenting with wireless power transfer. The maths to directly determine mutual inductance between two multi-layer rectangular coils of arbitrary area, separated by an arbitrary distance, ...
- 11
2
votes
1
answer
1k
views
How do I show for an ideal transformer $M^2=L_1L_2$?
I've been stuck on this problem for about an hour.
In an ideal transformer, the same flux passes through all turns of the primary and of the secondary . Show that in this case $M^2=L_1L_2$, where $...
- 5,371
2
votes
2
answers
47k
views
Magnetic field at the center and ends of a long solenoid [closed]
A long solenoid has current $I$ flowing through it, also denote $N$ as the turns per unit length. Take its axis to be the $z$-axis, by symmetry the only component of the magnetic field inside is $B_z$....
- 73
1
vote
1
answer
1k
views
Is Magnetic field inside solenoid dependant on volume of its shape?
There are two types of solenoids: one cylindrical, one spherical. Let's assume the dimensions of the cylindrical solenoid are set such that its base radius is that of spherical solenoid $a$, and the ...
- 265