{
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"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter4-Electron Ballistics"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex1-pg44"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"##Example 4.1\n",
"##Calculation of acceleration,time taken,distance covered and kinetic energy of an accelerating proton\n",
"\n",
"##given values\n",
"m=1.67 *10**-27;##mass of proton in kg\n",
"q=1.602 *10**-19;##charge of proton in Coulomb\n",
"v1=0;##initial velocity in m/s\n",
"v2=2.5*10**6;##final velocity in m/s\n",
"E=500.;##electric field strength in V/m\n",
"##calculation\n",
"a=E*q/m;##acceleration\n",
"print'%s %.1f %s'%('acceleration of proton in (m/s^2) is:',a,'');\n",
"t=v2/a;##time\n",
"print'%s %.5f %s'%('time(in s) taken by proton to reach the final velocity is:',t,'');\n",
"x=a*t**2./2.;##distance\n",
"print'%s %.1f %s'%('distance (in m)covered by proton in this time is:',x,'');\n",
"KE=E*q*x;##kinetic energy\n",
"print'%s %.3e %s'%('kinetic energy(in J) at the time is:',KE,'');\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"acceleration of proton in (m/s^2) is: 47964071856.3 \n",
"time(in s) taken by proton to reach the final velocity is: 0.00005 \n",
"distance (in m)covered by proton in this time is: 65.2 \n",
"kinetic energy(in J) at the time is: 5.219e-15 \n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex2-pg49"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"##Example 4.2\n",
"##electrostatic deflection\n",
"##given values\n",
"pi=3.141\n",
"V1=2000.;##in volts,potential difference through which electron beam is accelerated\n",
"l=.04;##length of rectangular plates\n",
"d=.015;##distance between plates\n",
"V=50.;##potential difference between plates\n",
"##calculations\n",
"alpha=math.atan(l*V/(2.*d*V1))*(180./pi);##in degrees\n",
"print'%s %.1f %s'%('angle of deflection of electron beam is:',alpha,'')\n",
"v=5.93*(10**5)*math.sqrt(V1);##horizontal velocity in m/s\n",
"t=l/v;##in s\n",
"print'%s %.3e %s'%('transit time through electric field is:',t,'')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"angle of deflection of electron beam is: 1.9 \n",
"transit time through electric field is: 1.508e-09 \n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex3-pg50"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"##Example 4.3\n",
"##electron projected at an angle into a uniform electric field\n",
"##given values\n",
"v1=4.5*10**5;##initial speed in m/s\n",
"alpha=37*math.pi/180.;##angle of projection in degrees\n",
"E=200.;##electric field intensity in N/C\n",
"e=1.6*10**-19;##in C\n",
"m=9.1*10**-31;##in kg\n",
"a=e*E/m;##acceleration in m/s**2\n",
"t=2*v1*math.sin(alpha)/a;##time in s\n",
"print'%s %.2e %s'%('time taken by electron to return to its initial level is:',t,'')\n",
"H=(v1**2.*math.sin(alpha)*math.sin(alpha))/(2.*a);##height in m\n",
"print'%s %.4f %s'%('maximum height reached by electron is:',H,'')\n",
"s=(v1**2.)*(2.*math.sin(alpha)*math.cos(alpha))/(2.*a);##print'%s %.1f %s'%lacement in m\n",
"print'%s %.4f %s'%('horizontal displacement(in m)when it reaches maximum height is:',s,'')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"time taken by electron to return to its initial level is: 1.54e-08 \n",
"maximum height reached by electron is: 0.0010 \n",
"horizontal displacement(in m)when it reaches maximum height is: 0.0028 \n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex4-pg53"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"##Example 4.4\n",
"##motion of an electron in a uniform magnetic field\n",
"##given values\n",
"V=200.;##potential difference through which electron is accelerated in volts\n",
"B=0.01;##magnetic field in wb/m**2\n",
"e=1.6*10**-19;##in C\n",
"m=9.1*10**-31;##in kg\n",
"v=math.sqrt(2.*e*V/m);##electron velocity in m/s\n",
"print'%s %.1f %s'%('electron velocity is:',v,'')\n",
"r=m*v/(e*B);##in m\n",
"print'%s %.4f %s'%('radius of path (in m)is:',r,'')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"electron velocity is: 8386278.7 \n",
"radius of path (in m)is: 0.0048 \n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex5-pg54"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"##Example 4.5\n",
"##motion of an electron in a uniform magnetic field acting at an angle\n",
"##given values\n",
"v=3*10**7;##electron speed\n",
"B=.23;##magnetic field in wb/m**2\n",
"q=45*math.pi/180;##in degrees,angle in which electron enter field\n",
"e=1.6*10**-19;##in C\n",
"m=9.1*10**-31;##in kg\n",
"R=m*v*math.sin(q)/(e*B);##in m\n",
"print'%s %.5f %s'%('radius of helical path is:',R,'')\n",
"p=2*math.pi*m*v*math.cos(q)/(e*B);##in m\n",
"print'%s %.4f %s'%('pitch of helical path(in m) is:',p,'')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"radius of helical path is: 0.00052 \n",
"pitch of helical path(in m) is: 0.0033 \n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex6-pg55"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"##Example 4.6\n",
"##Magnetostatic deflection\n",
"##given values\n",
"D=.03;##deflection in m\n",
"m=9.1*10**-31;##in kg\n",
"e=1.6*10**-19;##in C\n",
"L=.15;##distance between CRT and anode in m\n",
"l=L/2.;\n",
"V=2000.;##in voltsin wb/\n",
"B=D*math.sqrt(2.*m*V)/(L*l*math.sqrt(e));##in wb/m**2\n",
"print'%s %.4f %s'%('transverse magnetic field acting (in wb/m^2)is:',B,'')\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"transverse magnetic field acting (in wb/m^2)is: 0.0004 \n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Ex7-pg57"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"##Example 4.7\n",
"##electric and magnetic fields in crossed configuration\n",
"##given values\n",
"B=2*10**-3;##magnetic field in wb/m**2\n",
"E=3.4*10**4;##electric field in V/m\n",
"m=9.1*10**-31;##in kg\n",
"e=1.6*10**-19;##in C\n",
"v=E/B;##in m/s\n",
"print'%s %.1f %s'%('electron speed is:',v,'')\n",
"R=m*v/(e*B);##in m\n",
"print'%s %.3f %s'%('radius of circular path (in m) when electric field is switched off',R,'')"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"electron speed is: 17000000.0 \n",
"radius of circular path (in m) when electric field is switched off 0.048 \n"
]
}
],
"prompt_number": 7
}
],
"metadata": {}
}
]
}