# Variables
v = 230.; #in volts
d = 0.005; #in m
# Calculations
E = -v/d; #in V/m
# Results
print "Electric field between pair of conducting plates (in V/m) = ",E
# Variables
n = 10.**19; #no. of electrons per unit volume
e = 1.602*10**-19; #charge of an electron in C
a = 0.018; #conductivity in ohm/m
m = 9.1*10**-31; #mass of an electron in kg
v = 0.16; #in volts
t = 0.29; #thickness in mm
# Calculations
efg = v/t; #electric field gradient in V/m
vd = a*efg/(n*e);
vd1 = 10**3*vd; #in m/s
# Results
print "Drift Velocity (in m/sec) = %.3f m/s"%vd1
# Variables
l = 200.; #in m
r = 21.; #in ohm
d = 0.44*10**-3; #in m
# Calculations
a = 3.14*(d/2)**2; #area in sq m
p = r*a/l; #in ohm-m
# Results
print "Specific Resistance (in ohm-m) = %.3e ohm-m"%p
# Variables
p_cu = 0.015*10**-6; #resistivity of copper in ohm-m
p_ni = 0.012*10**-6; #resistivity of nickel in ohm-m
p_ag = 0.016*10**-6; #resistivity of silver in ohm-m
c1 = 0.25; #atomic % of nickel
c2 = 0.4; #atomic % of silver
# Calculations
p = p_cu+(c1*p_ni)+(c2*p_ag);
# Results
print "Resistivity of Cu-Ni-Ag alloy at 300 K (in ohm-m) = %.2e ohm m"%p
# Variables
m = 0.14; #mobility of electron
u_h = 0.05; #mobility of holes
p = 3000.; #resistivity in ohm-m
# Calculations
e = 1.602*10**-19; #charge of an electron in C
a = 1./p; #conductivity
n = a/(e*(m+u_h));
# Results
print "Intrinsic Carrier density in pure silicon (in per cu m) = %.3e m**3"%n
# Variables
id = 1000.; #in A/sqm
p = 0.05; #resistivity in ohm-m
l = 100.*10**-6; #in m
m_e = 0.4; #in sqm/Vsec
e = 1.602*10**-19; #charge of electron in C
# Calculations
a = 1./p; #conductivity
n_e = a/(e*m_e); #in per cubic m
v_d = id/(n_e*e); #in m/s
t = l/v_d; #in sec
t1 = t*10**6; #in msec
# Results
print "Drift Velocity (in m/s) = %.f m/s"%v_d
print "Time taken by electrons (in msec) = %.f ms"%t1
# Variables
d = 1.*10**-3; #diameter in m
a = 3.14*(d/2)**2; #area of cross section of rod in sq m
r = 100.; #in ohm
# Calculations
l = 10.*10**-3; #in m
p = a*r/l; #in ohm-m
c = 1./p; #conductivity
e = 1.602*10**-19; #charge of electron in C
u_h = 0.19; #mobility of holes in sqm/Vsec
n_h = c/(e*u_h);
# Results
print "Impurity concentration in rod (in per cubic m) = %.2e m**3"%n_h
# Variables
ni = 1.5*10**16; #intrinsic carrier concentration per cu. m
n = 10**19; #no. of conduction electrons in per cu. m
# Calculations
p = ni**2/n; #in per cu.m
# Results
print "Conduction electron and hole density (per cubic m) = %.2e m**3"%p
import math
# Variables
nd = 10.**17; #in per cu cm
ni = 1.5*10**10; #in cu cm
t = 300; #in K
# Calculations
ne = nd; #nd>>ni
nh = ni**2/ne;
e = 0.0259*math.log(ne/ni); #in eV
# Results
print "Hole concentration (in per cubic cm) = %.2e /cm**3"%nh
print "Location of Fermi Level (in eV) = %.3f eV"%e
# Variables
d = 40000.; #dielectric strength in V/mm
v = 33*10.**3; #in volts
# Calculations
t = v/d; #in mm
# Results
print "thickness of insulation (in mm) = %.3f m m"%t
# Calculation
T = 0.0464*10**5/2.9444
# Result
print "Temperature T = %.1f K"%T
# Variables
c = 2.99*10**8; #speed of light in m/s
h = 6.62*10**-24; #planck's constant
l = 1.771*10**-6 #wavelength in m
# Calculations
eg = (h*c)/l; #in J
# Results
print "Band gap energy (in J) = %.2e Joules"%eg
#Incorrect answer int the textbook. Please calculate manually