#importing modules
import math
from __future__ import division
#Variable declaration
c=3*10**8; #velocity of light(m/s)
m=1.67*10**-27; #mass of proton(kg)
h=6.626*10**-34; #planck's constant
#Calculation
lamda=h*10/(m*c); #de broglie wavelength(m)
#Result
print "de broglie wavelength is",round(lamda*10**14,3),"*10**-14 m"
#importing modules
import math
from __future__ import division
#Variable declaration
V=400; #voltage(V)
#Calculation
lamda=12.26/math.sqrt(V); #de broglie wavelength(angstrom)
#Result
print "de broglie wavelength is",lamda,"angstrom"
#importing modules
import math
from __future__ import division
#Variable declaration
m=1.674*10**-27; #mass of proton(kg)
h=6.626*10**-34; #planck's constant
E=0.025*1.6*10**-19; #energy(J)
#Calculation
lamda=h/math.sqrt(2*m*E); #de broglie wavelength(m)
#Result
print "de broglie wavelength is",round(lamda*10**9,3),"nm"
#importing modules
import math
from __future__ import division
#Variable declaration
V=1600; #voltage(V)
#Calculation
lamda=12.26/math.sqrt(V); #de broglie wavelength(angstrom)
#Result
print "de broglie wavelength is",lamda,"angstrom"
#importing modules
import math
from __future__ import division
#Variable declaration
deltax=0.2*10**-10; #distance(m)
h=6.626*10**-34; #planck's constant
#Calculation
deltap=h/(2*math.pi*deltax); #uncertainity in momentum(kg m/s)
#Result
print "uncertainity in momentum is",round(deltap*10**24,2),"*10**-24 kg m/s"
#importing modules
import math
from __future__ import division
#Variable declaration
n1=n2=n3=1;
h=6.62*10**-34; #planck's constant
m=9.1*10**-31; #mass(kg)
L=0.1*10**-9; #side(m)
#Calculation
E1=h**2*(n1**2+n2**2+n3**2)/(8*m*1.6*10**-19*L**2); #lowest energy of electron(eV)
#Result
print "lowest energy of electron is",round(E1,1),"eV"
#importing modules
import math
from __future__ import division
#Variable declaration
n1=n2=n3=1;
h=6.62*10**-34; #planck's constant
m=8.5*10**-31; #mass(kg)
L=10**-11; #side(m)
#Calculation
E111=h**2*(n1**2+n2**2+n3**2)/(8*m*1.6*10**-19*L**2); #lowest energy of electron(eV)
E112=6*h**2/(8*m*1.6*10**-19*L**2); #value of E112(eV)
E121=E112; #value of E121(eV)
E211=E112; #value of E211(eV)
E122=9*h**2/(8*m*1.6*10**-19*L**2); #value of E122(eV)
E212=E122; #value of E212(eV)
E221=E122; #value of E221(eV)
#Result
print "lowest energy of electron is",round(E111/10**4,3),"*10**4 eV"
print "value of E112, E121, E211 is",round(E121/10**4,4),"*10**4 eV"
print "value of E122, E212, E221 is",round(E122/10**4,3),"*10**4 eV"
#importing modules
import math
from __future__ import division
#Variable declaration
m=9.1*10**-31; #mass of electron(kg)
h=6.626*10**-34; #planck's constant
E=2000*1.6*10**-19; #energy(J)
#Calculation
lamda=h/math.sqrt(2*m*E); #de broglie wavelength(m)
#Result
print "de broglie wavelength is",round(lamda*10**9,4),"nm"
#importing modules
import math
from __future__ import division
#Variable declaration
m=9.1*10**-31; #mass of electron(kg)
h=6.626*10**-34; #planck's constant
n=1;
L=4*10**-10; #side(m)
#Calculation
E1=n**2*h**2/(8*m*L**2); #lowest energy of electron(joule)
#Result
print "lowest energy of electron is",round(E1*10**18,3),"*10**-18 joule"
print "answer varies due to rounding off errors"
#importing modules
import math
from __future__ import division
#Variable declaration
m=9.1*10**-31; #mass of electron(kg)
h=6.626*10**-34; #planck's constant
n1=1;
n2=2;
n3=3;
L=1*10**-10; #side(m)
#Calculation
E1=n1**2*h**2/(8*m*L**2); #lowest energy of electron(joule)
E2=n2**2*h**2/(8*m*L**2); #energy of electron in 1st state(joule)
E3=n3**2*h**2/(8*m*L**2); #energy of electron in 2nd state(joule)
#Result
print "lowest energy of electron is",round(E1*10**17,4),"*10**-17 joule"
print "energy of electron in 1st state is",round(E2*10**17,3),"*10**-17 joule"
print "energy of electron in 2nd state is",round(E3*10**17,3),"*10**-17 joule"
#importing modules
import math
from __future__ import division
#Variable declaration
m=9.1*10**-31; #mass of electron(kg)
h=6.626*10**-34; #planck's constant
lamda=1.66*10**-10; #wavelength(m)
#Calculation
v=h/(m*lamda); #velocity(m/s)
KE=(1/2)*m*v**2; #kinetic energy(eV)
#Result
print "velocity is",int(v/10**3),"km/s"
print "kinetic energy is",round(KE/(1.6*10**-19),2),"eV"
#importing modules
import math
from __future__ import division
#Variable declaration
V=15000; #voltage(V)
#Calculation
lamda=12.26/math.sqrt(V); #de broglie wavelength(angstrom)
#Result
print "de broglie wavelength is",round(lamda,1),"angstrom"
#importing modules
import math
from __future__ import division
#Variable declaration
V=344; #voltage(V)
n=1;
theta=60*math.pi/180; #angle(radian)
#Calculation
lamda=round(12.26/math.sqrt(V),3); #de broglie wavelength(angstrom)
d=n*lamda/(2*math.sin(theta)); #spacing of crystal(angstrom)
#Result
print "spacing of crystal is",round(d,4),"angstrom"
#importing modules
import math
from __future__ import division
#Variable declaration
E=1.5*9.1*10**-31; #energy(joule)
m=1.676*10**-27; #mass(kg)
h=6.62*10**-34; #planck's constant
#Calculation
v=math.sqrt(2*E/m);
lamda=h/(m*v); #wavelength(m)
#Result
print "wavelength is",round(lamda*10**6,3),"*10**-6 m"
print "answer varies due to rounding off errors"