# Chapter 17 Development of wave Mechanics¶

## Example 17.1 Page no 102¶

In [4]:
#Given
h=6.6*10**-34                        #j-s
v=6*10**14                           #/sec
w=6000*10**-10                       #m
c=3*10**8
e=1.6*10**-19

#Calculation
E=(h*(v-(c/w)))/e

#Result
print"Energy of photoelectrons is",round(E,3),"ev"

Energy of photoelectrons is 0.412 ev


## Example 17.2 Page no 102¶

In [17]:
#Given
w=4.8*10**-7
a0=2.3
h=6.6*10**-34
c=3*10**8
e=1.6*10**-19

#Calculation
hv=h*c/(w*e)
K=hv-a0
W=(h*c)/(a0*e)

#Result
print"Maximum kinetic energy is", round(K,2),"ev"
print"Longest wavelength is",round(W*10**7,2)*10**-7,"m"

Maximum kinetic energy is 0.28 ev
Longest wavelength is 5.38e-07 m


## Example 17.3 Page no 103¶

In [34]:
#Given
h=6.62*10**-34                         #joule-sec
m=9.1*10**-31
e=1.6*10**-19
E=1.25                           #Joule

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

#Result
print"Wavelength is",round(w*10**10,0),"A"

Wavelength is 11.0 A


## Example 17.4 Page no 103¶

In [39]:
#Given
h=6.6*10**-34                        #J-s
m=1.674*10**-27                      #Kg
w=10**-10                            #m

#Calculation
E=(h**2/(2*m*w**2))/e

#Result
print"Energy of neutron is", round(E,4),"ev"

Energy of neutron is 0.0813 ev


## Example 17.5 Page no 103¶

In [48]:
#given
w=4000*10**-10              #m
c=3*10**8                    #m/s
h=6.62*10**-34                 #js

#Calculation
v=c/w
E=(h*v)/e

#Result
print"Frequency is", v*10**-15,"*10**15 Hz"
print"Energy is",round(E,1),"ev"

Frequency is 0.75 *10**15 Hz
Energy is 3.1 ev


## Example 17.6 Page no 104¶

In [52]:
#Given
h=6.62*10**-34                   #J-s
m=1.67*10**-27                   #Kg
K=1.38*10**-23                   #Joule/K
T=300                            #K

#Calculation
import math
w=h/(math.sqrt(2*m*K*T))

#Result
print"Wavelength is",round(w*10**10,2),"A"

Wavelength is 1.78 A


## Example 17.7 Page no 104¶

In [57]:
#Given
m=1.67*10**-27                  #Kg
h=6.62*10**-34                    #joule-sec
V=2000                             #V

#Calculation
import math
M=4*m
w=h/(math.sqrt(4*M*e*V))

#Result
print"De-Broglie wavelength is",round(w*10**13,1),"*10**-3 A"

De-Broglie wavelength is 2.3 *10**-3 A


## Example 17.8 Page no 105¶

In [65]:
#Given
h=6.626*10**-34                  #j-s
m=9.1*10**-31                    #Kg
v=10**7

#Calculation
w=h/(m*v)

#Result
print"De-Broglie wavelength is",round(w*10**10,4),"A"

De-Broglie wavelength is 0.7281 A