Calculation of vector potential for a given magnetic field

[@mikefredd3390]

I appreciate that you go through some basic calculations of A. This subject is not treated well in many courses other that noting that A(r) like V(r) exists.

[@deepanshuchaudhary986]

The direction of A is always supposed to be in the direction of current. But in the 2nd example, direction of A is in negative z axes. Also, at s=infinity, A was assumed to be zero in the 2nd example but according to the equation, A depends on -ln(s) so how does A tend to zero when s tends to infinity?? Please explain

[@deepachauhan9365]

Good evening sir
Thanku sir 😃

[@prashjain0007]

@9:19 How B is uNI ? there should be r also

[@satyajitprasad6872]

Go check for the B due to a solenoid in any book or net….. BL = u. nLI gives it

[@prashjain0007]

@@satyajitprasad6872 dimensions are not matching.

[@satyajitprasad6872]

See actually n = no.of turns per unit length * Length * I gives current for a length of L in a solenoid with N turns

[@prashjain0007]

@@satyajitprasad6872 got it. Thanks. I missed that point

[@vishnusankar5335]

In example 2 you have taken the limits of the integral as infinity and s, but you have written only ln(s), where did ln(infinity) go? The assumption that A(infinity)=0 is not obeyed when s' is infinity. Please correct me if I am wrong.

[@Deban.jannnn]

??

[@dakshchhabra5975]

@@Deban.jannnn We have to consider only dependence of A on s

[@diegonavia1404]

I have this same question can someone please explain

[@dakshchhabra5975]

@@diegonavia1404
We want to se variation of A with respect to distance s. We use Vector potential to calculate magnetic field. Since magnetic field equals curl of vector potential and culr of constant is zero. You can ignore that infinity.

[@diegonavia1404]

@@dakshchhabra5975 damn, I see now. thank you

[@trishabhaad743]

Why does j in z direction give B in phi direction?

[@pandav01]

Very nice lecure Sir

[@kandiecarren7157]

Appreciate

[@Codem750]

why in the last example is minus