Question

For a 3p electron in an external magnetic field of 1.90 x10^-3 T, find the following.

(a)the current (in A) associated with the orbital angular momentum

(b)the maximum torque (in N · m)

Answer 1

part A : angular momentm L = mvr = nh/2pi

L = 3* 6.624*10^-34/(2pi)

L = 3.16*10^-34 kgm/s

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time T = 2pi R /Vn

Vn = n^2 * (0.529 )*10^-9/Z  

Vn = 3^2 * 0.529 *10^-9 /1

Vn = 4.761 *10^-9 m/s

now use Time = 2piR/Vn

R = 0.529 E-9

Current I = chrage/time  

I = 1.6*10^-19/time

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b) TOrque T = u x B

B is given in the question

u =magnetic moment = i x A  

A is area = pir ^2

find torque now