Recent content by kjintonic

Homework Statement A circular pan of radius b has a plastic bottom and metallic side wall of height h. It is filled with a solution of resistivity p. A metal disk of radius a and height h is placed at the center of the pan. The side and disk are perfect conductors. what's the resistance...

bump?

hmmm... Sorry I kinda don't understant how to write dq in terms of d[itex]d\theta[itex] :(

Probably I can use E= (S)dE= (S)kdq/r^2 inwhich r=a (S) is integral sign

A semicircular loop of radius a carries positive charge Q distributed uniformly over its length.? Find the electric field at the center of the loop (point P in the figure). Hint: Divide the loop into charge elements dq as shown in the figure, and write dq in terms of the angle d\theta. Then...

o cool :D Thanks a lot. One last question. This does prove that the quad falls off as 1/x^4 but how do i get field to the right of x=a?

Thanks a lot for the help. I simplified that combined faction and got \: (6a^2x^2-a^2)/(x^6-2a^2x^4+a^4x^2). I can't see any more way to simplify it :(

Homework Statement "An electric quadrupole consists of two oppositely charged dipoles in close proximity. (a) Calculate the field of the quadrupole shown in the diagram for points to the right of x = a, and (b) show that for x>>a the quadrupole field falls off as \frac{1}{x^4}"...

K now I understand that you have to use coulomb's law but how on Earth do i find q of one dipole?

I really don't know... I am a 11th grader and I'm asked to do university stuff;; oops i forgot the diagram ----- (- +) ---------------------------------(- +)---- --------a--------------------x-----------------a EDIT: You mean kq1q2/r^2 ??

Homework Statement Two identical dipoles, each of charge q and separation a, are a distance x apart, as shown in Fig. By considering forces between pairs of charges in the different dipoles, calculate the net force between the dipoles. Show that, in the limit a<<x, the force has magnitude...