1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
|
{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# 11: Magnetic Properties"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example number 1, Page number 11.31"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"temperature rise is 8.43 K\n"
]
}
],
"source": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"El=10**-2*50; #energy loss(J)\n",
"H=El*60; #heat produced(J)\n",
"d=7.7*10**3; #iron rod(kg/m**3)\n",
"s=0.462*10**-3; #specific heat(J/kg K)\n",
"\n",
"#Calculation\n",
"theta=H/(d*s); #temperature rise(K)\n",
"\n",
"#Result\n",
"print \"temperature rise is\",round(theta,2),\"K\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example number 2, Page number 11.31"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"magnetic field at the centre is 14 weber/m**2\n",
"dipole moment is 9 *10**-24 ampere/m**2\n"
]
}
],
"source": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"e=1.6*10**-19; #charge(coulomb)\n",
"new=6.8*10**15; #frequency(revolutions per second)\n",
"mew0=4*math.pi*10**-7;\n",
"R=5.1*10**-11; #radius(m)\n",
"\n",
"#Calculation\n",
"i=round(e*new,4); #current(ampere)\n",
"B=mew0*i/(2*R); #magnetic field at the centre(weber/m**2)\n",
"A=math.pi*R**2;\n",
"d=i*A; #dipole moment(ampere/m**2)\n",
"\n",
"#Result\n",
"print \"magnetic field at the centre is\",int(round(B)),\"weber/m**2\"\n",
"print \"dipole moment is\",int(round(d*10**24)),\"*10**-24 ampere/m**2\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example number 3, Page number 11.31"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"intensity of magnetisation is 5 ampere/m\n",
"flux density in material is 1.257 weber/m**2\n"
]
}
],
"source": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"chi=0.5*10**-5; #magnetic susceptibility\n",
"H=10**6; #field strength(ampere/m)\n",
"mew0=4*math.pi*10**-7;\n",
"\n",
"#Calculation\n",
"I=chi*H; #intensity of magnetisation(ampere/m)\n",
"B=mew0*(I+H); #flux density in material(weber/m**2)\n",
"\n",
"#Result\n",
"print \"intensity of magnetisation is\",int(I),\"ampere/m\"\n",
"print \"flux density in material is\",round(B,3),\"weber/m**2\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example number 4, Page number 11.31"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"number of Bohr magnetons is 2.22 bohr magneon/atom\n"
]
}
],
"source": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"B=9.27*10**-24; #bohr magneton(ampere m**2)\n",
"a=2.86*10**-10; #edge(m)\n",
"Is=1.76*10**6; #saturation value of magnetisation(ampere/m)\n",
"\n",
"#Calculation\n",
"N=2/a**3;\n",
"mew_bar=Is/N; #number of Bohr magnetons(ampere m**2)\n",
"mew_bar=mew_bar/B; #number of Bohr magnetons(bohr magneon/atom)\n",
"\n",
"#Result\n",
"print \"number of Bohr magnetons is\",round(mew_bar,2),\"bohr magneon/atom\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example number 5, Page number 11.32"
]
},
{
"cell_type": "code",
"execution_count": 8,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"average magnetic moment is 2.79 *10**-3 bohr magneton/spin\n"
]
}
],
"source": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"mew0=4*math.pi*10**-7;\n",
"H=9.27*10**-24; #bohr magneton(ampere m**2)\n",
"beta=10**6; #field(ampere/m)\n",
"k=1.38*10**-23; #boltzmann constant\n",
"T=303; #temperature(K)\n",
"\n",
"#Calculation\n",
"mm=mew0*H*beta/(k*T); #average magnetic moment(bohr magneton/spin)\n",
"\n",
"#Result\n",
"print \"average magnetic moment is\",round(mm*10**3,2),\"*10**-3 bohr magneton/spin\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example number 6, Page number 11.32"
]
},
{
"cell_type": "code",
"execution_count": 11,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"hysteresis loss per cycle is 188 J/m**3\n",
"hysteresis loss per second is 9400 watt/m**3\n",
"power loss is 1.23 watt/kg\n"
]
}
],
"source": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"A=94; #area(m**2)\n",
"vy=0.1; #value of length(weber/m**2)\n",
"vx=20; #value of unit length\n",
"n=50; #number of magnetization cycles\n",
"d=7650; #density(kg/m**3)\n",
"\n",
"#Calculation\n",
"h=A*vy*vx; #hysteresis loss per cycle(J/m**3)\n",
"hs=h*n; #hysteresis loss per second(watt/m**3)\n",
"pl=hs/d; #power loss(watt/kg)\n",
"\n",
"#Result\n",
"print \"hysteresis loss per cycle is\",int(h),\"J/m**3\"\n",
"print \"hysteresis loss per second is\",int(hs),\"watt/m**3\"\n",
"print \"power loss is\",round(pl,2),\"watt/kg\""
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example number 8, Page number 11.33"
]
},
{
"cell_type": "code",
"execution_count": 13,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"critical field is 33.64 *10**3 ampere/m\n"
]
}
],
"source": [
"#importing modules\n",
"import math\n",
"from __future__ import division\n",
"\n",
"#Variable declaration\n",
"H0=64*10**3; #initial field(ampere/m)\n",
"T=5; #temperature(K)\n",
"Tc=7.26; #critical temperature(K)\n",
"\n",
"#Calculation\n",
"H=H0*(1-(T/Tc)**2); #critical field(ampere/m)\n",
"\n",
"#Result\n",
"print \"critical field is\",round(H/10**3,2),\"*10**3 ampere/m\""
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 2",
"language": "python",
"name": "python2"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 2
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython2",
"version": "2.7.11"
}
},
"nbformat": 4,
"nbformat_minor": 0
}
|
