Chapter 29 Wave Nature Of Matter

Example 29.1 Page no 815

In [9]:
#Given
h=6.62*10**-34                      #Js
Me=9.1*10**-31                      #Kg
Ve=10**5                            #m s**-1
Mp=1.67*10**-27                     #Kg
Vp=10**5                            #m s**-1

#Calculation
Le=h/(Me*Ve)
Lp=h/(Mp*Vp)

#Result
print"The de-broglie wavelength of electron is",round(Le*10**9,2),"*10**-9 m"
print"The de-broglie wavelenght of proton is",round(Lp*10**12,2),"*10**-12 m"

The de-broglie wavelength of electron is 7.27 10**-9 m
The de-broglie wavelenght of proton is 3.96 10**-12 m

Example 29.2 Page no 816

In [16]:
#Given
M0=9.1*10**-31                     #Kg
h=6.62*10**-34                     #J s
V=0.5                              #c
V1=1.5*10**8

#Calculation
import math
L=(h*math.sqrt(1-V**2))/(M0*V1)

#Result
print"The de-broglie wavelenght is",round(L*10**12,1),"*10**-12 m"

The de-broglie wavelenght is 4.2 10**-12 m

Example 29.3 Page no 816

In [23]:
#Given
h=6.6*10**-34                        #J s
m=9.1*10**-31                        #kg
Iev=1.6*10**-19                      #J
E=6.4*10**-17                        #J

#Calculation
L=h/(math.sqrt(2*m*E))

#Result
print"The de-broglie wavelenght of electron is",round(L*10**10,2),"A"

The de-broglie wavelenght of electron is 0.61 A

Example 29.4 Page no 816

In [30]:
#Given
T=300                         #K
K=1.38*10**-23                #J
h=6.62*10**-34
m=1.675*10**-27

#Calculation
E=(3/2.0)*K*T
L=h/(math.sqrt(2*m*E))

#Result
print"The de-broglie wavelenght associated with thermal neutrons is",round(L*10**10,3),"*10**-10 m"

The de-broglie wavelenght associated with thermal neutrons is 1.451 10**-10 m

Example 29.5 Page no 816

In [42]:
#Given
L=10**-10                     #m
h=6.62*10**-34
c=3*10**8
S=1.6*10**-19
m=9.11*10**-31                #kg

#Calculation
#For X-ray photon of wavelength
E=(h*c)/L
E1=E/S
#For electron of wavelength 
Mv=h/L
E2=(Mv**2)/(2*m)
E3=E2/S

#Result
print"Energy of electron is",round(E3,1),"eV"
print"It follows that X-ray photon has greater energy"

Energy of electron is 150.3 eV
It follows that X-ray photon has greater energy

Example 29.6 Page no 816

In [1]:
#Given
M=1.675*10**-27                          #kg
E=2.4*10**-17                            #J
h=6.62*10**-34

#Calculation
import math
L=h/(math.sqrt(2*M*E))

#Result
print"The de-broglie wavelength of neutron is",round(L*10**12,3)*10**-12," m"

The de-broglie wavelength of neutron is 2.335e-12  m

Example 29.7 Page no 816

In [54]:
#Given
V=50                       #kV
E=8.0*10**-15              #J
m=9.1*10**-31
h=6.62*10**-34

#Calculation
import math
L=h/(math.sqrt(2*m*E))

#Result
print"Energy of electron is",round(L*10**12,3),"*10**-12 m"

Energy of electron is 5.486 10**-12 m