#Variable declaration
q=1.0 #no of coulomb
e=1.6*10**-19 #charge on an electron
#Calculation
n=(q/e) #calculating no of electrons
#Result
print"No of electrons =",n
print"NOTE:Calculation mistake in book"
import math
#Variable declaration
g=9.8
m=4.5 #Massin [kg]
r=0.03 #radius in [m]
#Calculation
F=m*g #in Newton
q=math.sqrt(((r**2)*m*g)/(9*10**9)) #calculating q using F=(1/4*3.14*eo)*((q1*q2)/(r**2))
#Result
print"Charge = ",q,"C"
print"\nNOTE:Calculation mistake in book"
#Variable declaration
q1=2*10**-7 #charge in C
q2=3*10**-7 #charge in C
r=30*10**-2 #r in m
#Calculation
F=(9*10**9)*((q1*q2)/r**2) #calculating F
#Result
print"Force = %.e"%F,"N"
#Variable declaration
q1=1 #charge in C
q2=1 #charge in C
r=1 #r in m
#Calculation
F=(9*10**9)*((q1*q2)/r**2) #calculating F
#Result
print"Force = %.e"%F,"N"
#Variable declaration
m=9*10**-31 #mass of electron in kg
q=-3.2*10**-7 #charge in C
e=-1.6*10**-19 #charge on electron in C
#Calculation
n=(q/e) #calculating n
M=n*m #calculating mass transfered
#Result
print"(a):No. of electrons = ",n
print"(b):Mass transfered to polythene= ",M,"kg"
#Variable declaration
q1=1.6*10**-19 #charge in C
q2=-1.6*10**-19 #charge in C
r=10**-9 #r in m
#Calculation
F=(9*10**9)*((q1*q2)/r**2) #calculating F
#Result
print"Force=",F,"N"
#Variable declaration
Va=-10 #voltage in volts
W=100 #work in Joule
q=2 #charge in Coulomb
#Calculation
v=(Va)+(W/q) #calculating v
#Result
print"Voltage = ",v,"V"
import math
#Variable declaration
eo=(8.854*10**-12) #constant
E=2 #magnitude of electric field in N/C
r=0.5 #r in m
#Calculation
q=E*4*(math.pi)*(eo)*(r**2) #calculating charge
#Result
print"Charge= %.2e"%q,"C"
print"\nNOTE:Calcualtion mistake in book"
#Variable declaration
e=-1.6*10**-19 #charge on electron in Coulomb
q=20*10**-6 #charge in Coulomb
r1=0.1 #r1 in m
r2=0.05 #r2 in m
#Calculation
Va=9*10**9*(q/r1) #calculating voltage at A
Vb=9*10**9*(q/r2) #calculating voltage at B
V=Va-Vb #potential difference
W=V*e #calculating work done in joule
#Result
print"Work done to take the electron from A to B = ",W,"Joule"
#Variable declaration
q1=(2.0*10**-8) #charge in coulomb
q2=(-2.0*10**-8) #charge in coulomb
q3=(3.0*10**-8) #charge in coulomb
q4=(6.0*10**-8) #charge in coulomb
s=1.0 #side in m
#Calculation
V=(9.0*10**9)*(1.0/s)*(q1+q2+q3+q4) #calculating voltage
#Result
print"Voltage in Volts = ",V,"Volts"
print"\nNOTE:Calculation mistake in book"
#Variable declaration
eo=8.85*10**-12 #constant
q=2*10**-6 #charge in coulomb
l=9 #length in cm
#Calculation
fi=(q/eo) #calcualting flux in (N m square)/c
#Result
print"Flux through the surface=%2e"%fi,"N m^2/c"
import math
#Variable declaration
eo=8.85*10**-12 #constant
r=1.2 #r in m
t=80*10**-6 #surface sharge density in c/m square
#Calculation
q=t*4*(math.pi)*(r**2) #calculating charge
fi=q/eo #calculating flux
#Result
print"Flux=%g"%fi,"N c^-1 m^2"
import math
#Variable declaration
eo=8.85*10**-12 #constant
E=9*10**4 #Electric field in N/C
r=2*10**-2 #r in m
#Calculation
L=2*(math.pi)*E*eo*r #calculating linear charge density
#Result
print"Linear charge density = ",round(L,7),"cm^-1"
#Variable declaration
o=17*10**-22 #surface charge density in cm**-2
eo=8.85*10**-12 #constant
#Calculation
E=o/eo #calculating electric intensity in region III
#Result
print"Electric Intensity in regions I and II = 0"
print"Electric Intensity in region III = ",round(E,12),"N/C"
import math
#Variable declaration
r=0.05 # in m
eo=8.85*10**-12 #constant
q=10.0**-9 #charge at point P in Coulomb
#Calculation
E=q/(4*(math.pi)*eo*(r**2)) #calculating electric field
r1=0.2 #in m
V1=q/(4*(math.pi)*eo*r1) #calculating potential difference
#Result
print"Electric field= ",round(E),"v/m"
print"\nNOTE:Approximate answer is calculated in book\n\n"
print"Potential difference between two points = ",round(V1),"V"
import math
#Variable declaration
eo=8.85*10**-12 #constant
o=80.0*10**-6 #surface charge density in c/ square
r=1.2 #in m
#Calculation
q=o*(math.pi)*(r**2) #calculating charge in Coulomb
fi=q/eo #calculating electric flux
#Result
print"Charge= ",q,"C"
print"Electric flux = ",fi,"N m^2/c"
print"\nNOTE:Wrong answers in book\n"
#Variable declaration
V=250 #potential difference in Volt
C=10**-11 #capacitance in farad
#Calculation
q=C*V #calculating charge
#Result
print"Charge = ",q,"C"
#Variable declaration
r=6.4*10**6 #in m
#Calculation
C=r/(9*10**9) #calculating charge
#Result
print"Capacitance = ",round(C*10**6),"mu F"
#Variable declaration
C=2 #capacitance in Farad
d=0.5*10**-2 #distance in m
eo=8.85*10**-12 #constant
#Calculation
A=(C*d)/(eo) #calculating area
#Result
print"Area=%.2e"%A,"m^2"
import math
#Variable declaration
A=0.02 #area in m square
r=0.5 #r in m
#Calculation
d=(A/(4*(math.pi)*r)) #calculating distance
#Result
print"Distance between the plates = ",round(d*1000,2),"mm"
#Variable declaration
eo=8.85*10**-12 #constant
A=1 #area in m square
d=2*10**-3 #r in m
K=4 #constant
#Calculation
C=(K*eo*A)/d #calculating capacitance
#Result
print"Capacitance = ",C,"Farad"
#Variable declaration
cm=10*10**-6 #capacitance in Farad
K=2 #constant
#Calculation
co=cm/K #calculating co
#Result
print"capacity of capacitor with air between the plates= ",co*10**6,"muF"
#Variable declaration
v=100.0 #v in volt
c1=8.0*10**-6 #capacitance in Farad
c2=12.0*10.0**-6 #capacitance in Farad
c3=24.0*10.0**-6 #capacitance in Farad
cs=4.0/(10.0**6) #calculating series capacitance
#Calculation
cp=(c1+c2+c3) #calculating parallel capacitance
qs=cs*v #calculating charge
#Result
print"Equivalent Series capacitance,C= ",cs*10**6,"muF"
print"Equivalent parallel capacitance,Cp= ",cp*10**6,"muF"
print"charge on plate=%.e"%qs,"C"
#Variable declaration
C=9*10**-10 #capacitance in farad
V=100.0 #in volt
#Calculation
U=(1/2.0)*(C*(V**2)) #calculating energy stored
#Result
print"Energy stored = ",U,"J"
#Variable declaration
eo=8.85*10**-12 #constant
A=90.0*10**-4 #area in m square
d=2.5*10**-3 #distance in m
V=400.0 #in volt
#Calculation
C=(eo*A)/d #calculating capacitance
W=(1/2.0)*(C*(V**2)) #calculating electrical energy stored
#Result
print"Capacitance = ",C,"Farad"
print"Electrical Energy stored in capacitor =%.2e"%W,"J"
#Variable declaration
v=100 #v in volt
c1=1*10**-6 #capacitance in Farad
c2=2*10**-6 #capacitance in Farad
c3=3*10**-6 #capacitance in Farad
cs=6/11.0 #calculating series capacitance
#Calculation
cp=(c1+c2+c3) #calculating parallel capacitance
#Result
print"Equivalent Series capacitance = ",cs,"muF"
print"Equivalent parallel capacitance= ",cp*10**6,"muF"
print"Therefore Cp=(11*Cs)"
#Variable declaration
eo=8.85*10**-12 #constant
V=6 #v in volt
A=25*10**-4 #area in m square
d=10**-3 #distance in m
#Calculation
q=(eo*A*V)/d #calculating charge
W=q*V #calculating work done
#Result
print"Charge through battery =%.3g"%q,"C"
print"Work done by Battery=%.e"%W,"J"