while exploring the web for EDC content I came across this channel on youtube. wow, I have come to the right place for preparing. content and the way you deliver the concepts are really good. especially this lecture the lake analogy was a great one.
Complex explanation from textbook made me think this in a very complex way. I didn't think this could be understood in this easy way. Thank you very much from Bangladesh....
This is a very detailed and most importantly, clear explanation thank you. The only feedback I would give is that you did not fully explain why we consider the current going in and going out as being a separate cause to the generation and recombination rates. In other words, that equation suggests another mechanism for why the current entering the region can be less than the current exiting. I would have thought that the difference in the currents would contain the generation and recombination rates.
Kindly reply if anyone gets my question: dn/dt is +ve when g is greater and positive and dJ/dx is positive ..but dJ/dx is J(x+∆x)-J(x) .. so for dJ/dx to be positive J(x+∆x)>J(x) ..but we have seen that J(x+∆x) should be less than J(x) for no. Of electrons inside the box to be positive.... Plz clarify
if we divide the current density by charge q - we can get number of carriers flowing per unit area per unit time, which I believe is easier to understand and on top of it +ve charge and -ve charge are brought out to see the difference. Hope that helps. Thanks, Techgurukula.
The continuity equation for conductors in simple DC circuits is seldom found and derived in textbooks though derivations in case of semiconductors are found in several textbooks. The charge density and current density functions are related by the continuity equation (see Electricity and Magnetism by Edson Ruther Peck, McGraw Hill, 1953) which maybe derived by applying the principle of conservation of charge. Since most textbooks on circuit theory do not discuss this important aspect of the conduction process in the dc steady state in particular, I have discussed this in textbook 4 (see last frame of video 1 to be discussed below). In its most general form the equation of continuity is ∂J_x/∂x + ∂J_y/∂y + ∂J_z/∂z + ∂ρ/∂t = 0. (Eq. 1) as derived from the conservation of electric charge law. The current density J in an isotropic medium is given by the relation J = σE (Eq. 2) where E is the electric field intensity and where σ is the conductivity of the medium. It is also written from Eq. 1 as ∂J_x/∂x + ∂J_y/∂y + ∂J_z/∂z = 0. (Eq. 3) when there is no excess charge in the conductor or that there is no unpaired charge density (lattice ion and conduction electron). In the absence of emf in a region in the circuit (say, away from the source or battery and within a small section of the conductor or a resistor), the total electric field E, may be expressed in terms of a scalar potential function U; E_x = - ∂U/∂x E_y = - ∂U/∂x, and E_z = - ∂U/∂z (Eq. 4) Eqs. (2), (3) and (4) characterize the current flow within a region of a homogeneous, linear, isotropic conductor where there is no emf. If a dc circuit of a battery and a wire is laid in a straight line along the x-axis then evidently, the presence of surface charges will guarantee that the total field E will be a constant E_x along the axis in the region. Therefore, the solution of Eq. (3) gives J_x = a constant, so using Eq. 2, we get J_x = σE_x = I/A (Eq. 5) where σ is the conductivity of the wire, I is the current in the circuit and A the cross-sectional area of the wire. Eq. 5 is the equation of continuity applicable to the steady-state in a simple DC circuit. Electrostatics and circuits belong to one science not two and it is instructive to understand Current, the conduction process and Voltage at the fundamental level as in the following two videos: i. ua-cam.com/video/REsWdd76qxc/v-deo.html and ii. ua-cam.com/video/8BQM_xw2Rfo/v-deo.html The last frame References in video #1 lists textbook 4 in which a supplementary article “Charge Densities and Continuity and Prop of em signals in wires.pdf” in the pdf files folder in the CD discusses these topics in more detail with several diagrams using a unified approach and includes a description of the application of the general continuity equation in special situations like conductors in isolation and in semiconductors.
Because he needed to state the charge of the particle he is taking the count of (in this case a negatively charged electron), to satisfy the current density (Jn) parameter. Essentially he is saying negative current density, becuase current density is usually represented as positive he needs to multiply it by -q so now it is the negative current density, or current density of electrons. To further explain; when doing the math he already stated that Jn(x)>Jn( x+Δx), you can see for the continuity equation for electrons that if ∂Jn/∂x (while strictly holding flow is from the left) the current density is increasing across the material span. If the current density is increasing then we know that the electrons are decreasing because electron current density is -∂Jn/∂x, and so Jn(x)>Jn( x+Δx) holds. We achieved this state by substituiting -q. Furthermore we can see for the holes continuity equation that by leaving q as positive we have a negative infront of ∂Jn/∂x, therefore making decreases current across Δx positive which satisfies Jn(x)>Jn( x+Δx) for positive particles. In summary sub in -q for negative particles electrons for increasing electrons & +q for positive particles increasing positive charges. This video from Khan academy explaining diffusion & drift might help you: www.khanacademy.org/science/in-in-class-12th-physics-india/in-in-semiconductors/in-in-the-pn-junction/v/diffusion-drift-barrier-voltage-class-12-india-physics-khan-academy?modal=1
Excellently explained~
You are helping me in my 2nd year Btech in Electronics!
God bless you.
Hello sir i am in btech ec 2nd year. Help
Thank you so much. Greetings from an electrical engineer from Greece!
while exploring the web for EDC content I came across this channel on youtube. wow, I have come to the right place for preparing. content and the way you deliver the concepts are really good. especially this lecture the lake analogy was a great one.
Excellent video
Complex explanation from textbook made me think this in a very complex way. I didn't think this could be understood in this easy way. Thank you very much from Bangladesh....
This is a superb video...understood Continuity equation very welll!!!
Thank you so much Sir
masterpiece!! I bet no one could explain it better than you. Analogy also given. Thanks :)
i never thought it would be this easy!!!! thank you sir, a ton! 😊😍
Thank you..Most of my doubts are clear... Happy Teacher's Day...you people deserves it...for the very suitable analogy provided during the session..
Thanks a lot sir
.. Tomorrow is my exam this help me a lot
Good video, sir. Very well explained. Thanks.
Very nicely explained and to the point. All 11 mins is worth
What a simple n easy to understand. Thk you sir
Awesome explanation... finally understood the continuity equation
Please sir make videos for EMT
Great video!! It provides us with simple explanation
Simple.... And Excellent explanation
best and most easiest explanation ever....
This is a very detailed and most importantly, clear explanation thank you. The only feedback I would give is that you did not fully explain why we consider the current going in and going out as being a separate cause to the generation and recombination rates. In other words, that equation suggests another mechanism for why the current entering the region can be less than the current exiting. I would have thought that the difference in the currents would contain the generation and recombination rates.
What a concept sir....
Superb explanation!
great u explained it by making it look so easy spatially that LAKE example was awesome.....
Awesome way of explanation
Ur explanation is very conceptual unlike others. Keep it up . And also work on perfection
Ur every video I watch satisfies :)
Very Nicely Explained... Thank you very much... :)
excellent explanation, even a layman can understand!
Gr8 explaination Sir👌
Amazing Explanation!
fantastic expln.. no one can better explain than he did....
Excellent video. Thanks
Thanks.. For making the concepts so clear !!
how old r u? You must be super smart
at 4:13 first term indicates no of electrons flowing out of box,because when current enters electrons leave.Am I right?
thank you very much, very well explained
nice explanation
Excellent explained
thanks for providing me such a nice video
Sir haynes Shockley experiment is missing from your lecture series
Thank you sir i dont know what's going on but i can write this easily in exam 🤝💖
Best of Best Dear ♥
best video ever
Thanks a lot ..sir 😃😃
anology fadu thi btw
In a reference book
The continuity equation of electrons in P type semiconductors is having different sign from yours
(Can you say about this ?)
Does someone know , from where to refer Poissons equation?
Just pointing out. It's delta x not del x. del (.aka nabla) is the gradient.
Which software used in creating this video sir
thank u soo much for this video
please sir make video for mosfet before end of this month
Kindly reply if anyone gets my question:
dn/dt is +ve when g is greater and positive and dJ/dx is positive ..but dJ/dx is J(x+∆x)-J(x) .. so for dJ/dx to be positive J(x+∆x)>J(x) ..but we have seen that J(x+∆x) should be less than J(x) for no. Of electrons inside the box to be positive.... Plz clarify
Nice explaination but sir if possible please use better microphone thank you
Why devide the current density by charge q?
if we divide the current density by charge q - we can get number of carriers flowing per unit area per unit time, which I believe is easier to understand and on top of it +ve charge and -ve charge are brought out to see the difference.
Hope that helps.
Thanks,
Techgurukula.
Thnx a lot sir
thank U Sir.................
damn nice explanation!
Sit 3.0r time par jo current density wala ki x par jyada hogi to hi dn/dt badega kaise
thanks you very much
sir electromagnetic field theory par v plss videos bnaiye. humble request
Thank u
The continuity equation for conductors in simple DC circuits is seldom found and derived in textbooks though derivations in case of semiconductors are found in several textbooks.
The charge density and current density functions are related by the continuity equation (see Electricity and Magnetism by Edson Ruther Peck, McGraw Hill, 1953) which maybe derived by applying the principle of conservation of charge. Since most textbooks on circuit theory do not discuss this important aspect of the conduction process in the dc steady state in particular, I have discussed this in textbook 4 (see last frame of video 1 to be discussed below).
In its most general form the equation of continuity is
∂J_x/∂x + ∂J_y/∂y + ∂J_z/∂z + ∂ρ/∂t = 0. (Eq. 1) as derived from the conservation of electric charge law.
The current density J in an isotropic medium is given by the relation J = σE (Eq. 2)
where E is the electric field intensity and
where σ is the conductivity of the medium. It is also written from Eq. 1 as
∂J_x/∂x + ∂J_y/∂y + ∂J_z/∂z = 0. (Eq. 3)
when there is no excess charge in the conductor or that there is no unpaired charge density (lattice ion and conduction electron).
In the absence of emf in a region in the circuit (say, away from the source or battery and within a small section of the conductor or a resistor), the total electric field E, may be expressed in terms of a scalar potential function U;
E_x = - ∂U/∂x E_y = - ∂U/∂x, and
E_z = - ∂U/∂z (Eq. 4)
Eqs. (2), (3) and (4) characterize the current flow within a region of a homogeneous, linear, isotropic conductor where there is no emf.
If a dc circuit of a battery and a wire is laid in a straight line along the x-axis then evidently, the presence of surface charges will guarantee that the total field E will be a constant E_x along the axis in the region. Therefore, the solution of Eq. (3) gives J_x = a constant, so using Eq. 2, we get J_x = σE_x = I/A (Eq. 5) where σ is the conductivity of the wire, I is the current in the circuit and A the cross-sectional area of the wire.
Eq. 5 is the equation of continuity applicable to the steady-state in a simple DC circuit.
Electrostatics and circuits belong to one science not two and it is instructive to understand Current, the conduction process and Voltage at the fundamental level as in the following two videos:
i. ua-cam.com/video/REsWdd76qxc/v-deo.html and
ii. ua-cam.com/video/8BQM_xw2Rfo/v-deo.html
The last frame References in video #1 lists textbook 4 in which a supplementary article “Charge Densities and Continuity and Prop of em signals in wires.pdf” in the pdf files folder in the CD discusses these topics in more detail with several diagrams using a unified approach and includes a description of the application of the general continuity equation in special situations like conductors in isolation and in semiconductors.
Oh thank you so much.
Perfect...
why charge of electron is -q ?
abe yaar......
Because he needed to state the charge of the particle he is taking the count of (in this case a negatively charged electron), to satisfy the current density (Jn) parameter. Essentially he is saying negative current density, becuase current density is usually represented as positive he needs to multiply it by -q so now it is the negative current density, or current density of electrons.
To further explain; when doing the math he already stated that Jn(x)>Jn( x+Δx), you can see for the continuity equation for electrons that if ∂Jn/∂x (while strictly holding flow is from the left) the current density is increasing across the material span. If the current density is increasing then we know that the electrons are decreasing because electron current density is -∂Jn/∂x, and so Jn(x)>Jn( x+Δx) holds. We achieved this state by substituiting -q. Furthermore we can see for the holes continuity equation that by leaving q as positive we have a negative infront of ∂Jn/∂x, therefore making decreases current across Δx positive which satisfies Jn(x)>Jn( x+Δx) for positive particles. In summary sub in -q for negative particles electrons for increasing electrons & +q for positive particles increasing positive charges.
This video from Khan academy explaining diffusion & drift might help you: www.khanacademy.org/science/in-in-class-12th-physics-india/in-in-semiconductors/in-in-the-pn-junction/v/diffusion-drift-barrier-voltage-class-12-india-physics-khan-academy?modal=1
Thank you sir
Sehr gut
Upload some new videos🤗
Tq Sir.
THANKS
Thank You.
thanks a lot
before gate paper
Difficult
what is wrong with your accent ?
Thanks a lot sir