Consider an atomic dipole in which a proton and an electron are separated by a d
ID: 1428308 • Letter: C
Question
Consider an atomic dipole in which a proton and an electron are separated by a distance d = 0.1 nm (one angstrom). The proton is on the x axis at x = -d/2 and the electron Is on the x axis at x = d/2. What is the dipole moment p? (Give the direction of p anti give its magnitude in Debyes.) Draw the lines of E anti the equipotential surfaces as projected in the xy plane (the plane of the paper on which you are writing your solutions). Write down an expression for E at a location r along the y-axis. and show that E - p/4 pi epsilon_0 r^3 for r >> d.Explanation / Answer
P=ql = (1.6*10^-19)(0.05*10^-9) = 8.0*10^-30 Cm
E1=kq/BD^2 = kq/(r-l)^2 i ----------------(1)
E2=kq/aD^2 = - kq/(r+l)^2 - i ----------------(2)
Enet = E1+E2 = [kq/(r-l)^2] – [kq/(r-l)^2] = k(2r(q x 2l))/(r^2-l^2)^2
(qx2l) i = pi = P
Where p = dipole moment = ql
Enet= k2pr/r^4 = 2kp/r^3= (1/40)*(2p/r^3)