#importing modules
import math
from __future__ import division
#Variable declaration
chi=-4.2*10**-6; #magnetic susceptibility
H=1.2*10**5; #magnetic field(A/m)
mew0=4*math.pi*10**-7; #permitivity of free space(H/m)
#Calculation
M=chi*H; #magnetisation(A/m)
B=mew0*(H+M); #flux density(T)
mewr=(M/H)+1; #relative permeability
#Result
print "magnetisation is",M,"A/m"
print "flux density is",round(B,3),"T"
print "relative permeability is",round(mewr,6)
#importing modules
import math
from __future__ import division
#Variable declaration
Z=2; #atomic number
mew0=4*math.pi*10**-7; #permitivity of free space(H/m)
e=1.6*10**-19; #conversion factor from J to eV
m=9.1*10**-31; #mass of electron(kg)
N=28*10**26; #number of atoms(per m**3)
r=0.6*10**-10; #mean radius(m)
#Calculation
chi=-mew0*Z*e**2*N*r**2/(6*m); #diamagnetic susceptibility
#Result
print "diamagnetic susceptibility is",round(chi*10**8,3),"*10**-8"
#importing modules
import math
from __future__ import division
#Variable declaration
n=2;
a=2.55*10**-10; #lattice constant(m)
chi=5.6*10**-6; #susceptibility
Z=1;
mew0=4*math.pi*10**-7; #permitivity of free space(H/m)
e=1.6*10**-19; #conversion factor from J to eV
m=9.1*10**-31; #mass of electron(kg)
#Calculation
N=n/(a**3); #number of electrons per unit volume(per m**3)
rbar=math.sqrt(chi*6*m/(mew0*Z*e**2*N)); #radius of atom(m)
#Result
print "radius of atom is",round(rbar*10**10,3),"angstrom"
#importing modules
import math
from __future__ import division
#Variable declaration
mew0=4*math.pi*10**-7; #permitivity of free space(H/m)
k=1.38*10**-23; #boltzmann constant(J/K)
T=300; #temperature(K)
N=6.5*10**25; #number of atoms(per m**3)
mew=9.27*10**-24;
#Calculation
chi=mew0*N*mew**2/(3*k*T); #susceptibility
#Result
print "susceptibility is",round(chi*10**7,2),"*10**-7"
#importing modules
import math
from __future__ import division
#Variable declaration
rho=4370; #density(kg/m**3)
NA=6.02*10**26; #avagadro number(k/mole)
M=168.5; #molecular weight(kg/kmol)
mew0=4*math.pi*10**-7; #permitivity of free space(H/m)
k=1.38*10**-23; #boltzmann constant(J/K)
T=300; #temperature(K)
H=2*10**5; #electric field(A/m)
mew=2*9.27*10**-24;
#Calculation
N=rho*NA/M;
chi=mew0*N*mew**2/(3*k*T); #susceptibility
M=chi*H; #magnetisation(A/m)
#Result
print "susceptibility is",round(chi*10**4,4),"*10**-4"
print "magnetisation is",round(M,3),"A/m"
print "answer varies due to rounding off errors"