Newspaper Page Text
PnKc Twelve
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——■ I Mill - I ■ —■-.■ ■■■« mmm I..»l~l-H-
WHAT INDUCTANCE
MEANS EXPLAINED
Its Cause and Effects Arc H
Told in Popular
for the N
When a <
. ■
ductor i ■ ■ ■ :
for Its •
v liit tit!
t
i :.
til
A CO
■urroi
the va
In |
the
conductor will
! •■ in il a \ I
voltage in ii con \ a ■
change ii
produced by the
the electro-motive force ■
tlon. The dire* ■ lon ol
ne i" si' ■
tn oppose anj i
Lr> ■ a
if applied eurri ■ b
away from the n
In current will pi
Belf-inductiou that will a<lil
rent flow nwaj from (he
. \il!a." Al I ■■ In the How
of the current «i'l Increase the
■ d an •'. in. t. ol
ductlon v.v sll lu> Induced that will i>;>
pose the How of i
Suppose we consider the magnetic
field about a conductor currying an
alternating current. The current al
ternately flow In (Mir direction and
■*■ — / Cyc/c ■ >
—• . _ I _ rCurrent
djL i\a l£ ; p2_^__X—A /
£?L/£ 70
SZLF INDUCTION
then tlic other direction. Each time
the dlrei tlou of flow of the current
changes, the direction of the magnetic
field reverses.
When an alternating current flows
In v conductor, the current which in
6et up by the changing magnetic field I*
aKo alternating. Suppose tliul Fig. I
represents n graph of Ui>- current flow
Ing In the conductor. During the first
quarter of the cycle, while the cur
rent is Increasing from zero at A to
ti maximum value at B, the magnetic
field will build up with the .uncut.
The Inductive back c. in. f., which de
pends on the rate of change of flow,
will be a maximum at A, where the
flux is changing most rapidly, and a
minimum at B, where change In flow
is zero. Similarly during the other
three quarters of a cycle the Induced
c. in. f. due to Induction will be a
maximum at C ami X and v minimum
nt D.
Tin' dotted curve then In Fig. 1
represents the c. m. i\, of self-induc
tion. >>\>tf that there is a phase dif
ference of one-quarter of a cycle, or
flu electrical degrees, between t!><' c.
in. 1., due to Induction mid the current
producing the magnetic field. This
tlon of the conductor having a back
*. in. f. Induced In it, when a varying
current flows through the conductor is
called self-induction.
In other words, self-induction may
be defined us the property of an •
I circuit that tends to prevent any
cliuuge in the value of the circuit
flowing through it. The c, m. f. of self
induction is always In such a direction
us to prevent any change of current
In the circuit. A length of wire wound
In the form <>f a coll called a lolenold
has a greater self-induction than the
tame length of straight. The self-In
duction of a coil with no iron i
the magnetic Held is v constant
ilej ends on the physical dlinens
of the circuit. The unit of Induct
Is the henry. An electrical circuit has
an Inductance of one henry, when a
change In the current of one ampere
i nd will cause a back >• .m. f.
Of I !,'■ \
It but been explained that an ever
changing magnetic Held Burrounds a
circuit carrying an alternating current
ana 1 that this changing magnetic Held
induces in the. circuit a back c. m. f.
which opposes an) change in the cur
rent flowing in the circuit.
If a second electrical circuit is
brought within the magnetic tield of
the ttrst circuit, the second circuit will
have a voltage Induced in it. The val
ue of the voltage Induced in the sec
ond electrical circuit will be one volt
per 100,000,000 lues of flux cut per
• «id. The direction of the Induced
voltage .ii the second circuit will be
lfcu electrical degrees out or phase
With the applied voltage of the tirst
circuit. The phenomenon Just de
■cribed ib known as mutual induct-
UK*. Self-Induction Is the reaction of
» circuit upon Itself. Mutual induct
ance is the reaction that exists he
tweon two circuits linked by a inn*
netlc Held but separated electrically^
Bxamplei of both types of Induct
• found ii> both lii^rh and low
lii ;i radiophone trans
r n actancea are >'\
(juency self Indue
' am n tranj foriuer is an
ituul Inductance. The
tent transformer
Held tlml ;.■- cut by
i the second"
In radio fre
ining coll depends
mlin'tlon. The
■ : depends
n for the trans'
the primarj or
itndarj tuned
uppar-
atus is connected
Mnd
: current,
■ • unsld
• ■ > ] i -1:1111
on
• ■ . v Is
. . sec
tor bj the same back
il flowing
■ wuly i>\ er the cross
I ■
This is not truu In conductors car
rying nltermiting current. I here are
two voltages that oppose the Bow of
alternating current In ;i conductor.
First, the back voltage due to resist
ance, uii'l second, the back voltage in
duced by BiMf-lnductlon. Ihe magnet-
Ie field surrounding the conductor will
be strongest nl the center of the con
ductor and weaker at the surface (if
tllt< conductor. This will cause the
Induced back c. in. f. to he largest at
the center ami smallest nt the Burface
of the conductor. Naturally the den
sity of tin- circuit that Hows will he
Inversely proportional to this opposing
i. in. f. or the least current will flow
at the center nnd the greater current
will (low along the surface.
■ j of i lit- current la
the "ski i effect," as It is
I, becomes more and more pro
flounced. Finally n i radio frequi nci(
Fi ß . 1.
such a small quantity of current flows
near the center of the conductor that
(Inl conductive material there Is use
less anil can be removed. Fur this
reason tubing is often used for con
ducting high power at high frequen
cies.
•■•.•■■•..•..•..•..«..•..•.. f ■•■••.•■■■•-••■■••■•■■•■•••■••••■-•>••- <^
; RADIO SPARKS !
• ?
. Broadcasting descriptions of •
* misting persons is a new use of ;
. the art. f
I It is suggested that the growth |
* of radio in the next five years j
I will make necessary a "United !
t States secretary of communlca- •
I tions." !
♦ Radio Insurance Is now being ?
I offered covering (Ire, lightning, f
j breakage and theft. I
* When a crystal detector set Is t
I not In use it should always be 1
• disconnected from the antenna, f
I If this Is not done, sensitiveness i
t will be gradually destroyed by ?
. continual static splashes and t
? loud signals. $
I The army has perfected a i
I method by which the fastest- *
• Bent radio message can be I
I caught on wax cylinders and re- f
j produced at lower speed on die- f
i taphone machines, making the j
♦ message easy to read. T
| The first radio theater is to be f
? Installed In the Grand Central I
I hotel in New York city. It will {
I seal more than 1,000 persona '
* and will be made commodious I
? enough to accommodate a large t
i throng on a dancing floor in a i
| pavilion adjoining. Entertain* j
i mem and dance music will be I
I picked up from the air. ?
i Loose connections, poor Insula- ♦
; tlon, poor ground, poor joints |
. and wires, worn insulation, ?
t res crossing, and many other !
t small matters may put a set f
j completely out of commission. ;
* In 111• - Canary Islands the In- *
I habitants convey signals and bits *
t of news by v system of whistling. i
'. The system dates buck hundreds •
t of years. When radio takes hold I
| the islanders will not know *
• whether their apparatus is out '.
I of tune or some Inhabitant Is f
i trying to whistle a message. !
t Every motorcycle used by the *
| state police of Michigan will be •
f equipped with radio if expert- '
Si nn'i.ts now being conducted by •
* the state department for safety I
i are successful. f
! A Frenchman baa invented a *.
! system by which checks can be •
i sent by radio. What we now :
* want is a new and easy method t
| of making the money to meet the i
? checks. *
I A boy in Cambridge, Mass., t
t one evening received on his set {
! ■ time signal from Naueii, Ger- •
f many i and one from Honolulu. •
i.. ;
AN ENGAGEMENT PRESENT
"I've htiil Htl
If, i'HC-1 I '." <;ii<] Mi MM I]
It."
1 I
• ■ .1
\
f ■
■
■ ■
- - '
l"t im> 5.., It.
lien
"And I wimt to
SlH' it, I < ill ' »;|lil
Miss Rrnwn lie- 1.
"Sii (In I." siM
Red Top, tin
Monster. "I mi •
certainly wan: ti>
>c c It, CO!'l\ II
!■•!, ii,. i],, pray
slillW it t<) Hll. 1."
"I'd like to sin?
it." said Mi
Duck. '.'Quack;
•Let Me See "
k, please lei me see it."
"And 1 want to have a view of it
i n," snld Sir I (avid I >uck.
"What is all the fuss about?" asked
Mr. i iander, a- he walked bj the n
ird animals.
"( >'■• riotl Ing for us to bother
' s. Goose.
"I thought aa much," said Mr.
Gander.
".Miss lien is engaged to Robbie
Rooster nnd all the other barnyard
iniliniils want to see the present she
has been given which she calls her
engagement present," Mrs. Goose ex
plained.
"! don't waul to bother to see it,"
Mr. i lander. "I am sure you don't
want in bother either."
"No, I don't want. !<> bother," said
Mrs, Goose. "Such a thing would he
n w ;{>\r of our time. We can't bother
with the other lmrn.\nrd nnluuils.
"We prefer our own society."
"Jus! as we should do," said Mr
Gander. "Jusl as we should do."
"Let me see the present," bogged
Mrs. Indian Runner I >uck.
"I'd like to see It," said Sir William
\ known as Hilly by the !>:im
yard friends.
'•oil, show it to us," said Mrs Whit.'
Hen.
"I can't," said Miss Hen. "Cackle,
cackle, It is <jllir»■ Impossible. I can'!
"I would If 1 could, but it's Impos
Bible."
"How absurd," said Miss Fidgety
Fashionable Men.
"Ridiculous,," said Mrs. White Hen
"Utterly nonsensical," said Mis-
Brown Hen.
"Too queer tor words," said Red
Top, the Rooster,
"I cannot understand why she says
such a thing, quack, quack," said Mrs.
Duck.
"I don'l undi rstand, eithi r,"
sir David Duck."
"Tell old Billy Goat," said Sir William
< !oat.
"You see, said Miss Hen. "I can't
show you my engagement present. I
told you that I had been given an en
gagement present, hut I didn't say you
could sec it us that is so Impossible."
"Why is it impossible? Was it such
a horrid present that you are ashamed
to show It to us?" asked MN- drown
Men.
"Of course not," said Miss 11.mi
proudly. "My dear Robbie Renter
would only give me the very best.
"But It is impossible to show It to
i"U 88 I have eaten It! Ah, yes, It
wiis a beautiful engagement present
No hen was ever giveu so tine and
delicious a worm as Robbie picked out
for me.
"He said he looked them all over
and waited until he succeeded in get
ting the very best of all.
"Hut I have already puten my en
gagement present. And I thoroughly
enjoyed it."
"So tliiit was It, 1
Fashionable Hen.
said Miss Fidgety
"How stupid of
.!.-> not to have nn
ierstood."
"How stupid,"
-aid Mrs. Whit.'
Hen.
"Very stupid,"
said Miss Brown
Her..
"V o v He n b
* !1 0 il 1 d h a v c
thought of that,"
said Sir David
Hue!;.
"You hho v 1 d
have thought <>■
that. Hens. !t Is
true," said Mrs.
Duck,
"Our Own
Society."
"Well. I i,, J,t.
too, have thought
that it wus someihing you had eaten,"
said Billy Goal "'For an engagement
present that can be eaten is surely
nicer than any other, Is my goat opin
ion."
"And now rhpy all know," said Miss
Hen. "Ah, 1 kept them guessing while
all the time I « it - feeling bappj and
contented for I had received mj en-
mem present and had thoroughly
enjoyed It!"
How It Looked.
"I've been down by the river," an
nounced little Marjory, ••an,! I saw
•1 man sit there and drown three
worms."
Something Big and Clean.
Jones —l want to do something big
uu'i clean before I tile.
Bones —Wash uu elephant.
Tin: PULLMAN HERALD
COACH WKLCH QUITS
Jolt \s COUGAR MENTOR
i Continued from first page >
of Congressman Charles D. Cartel- of
Ardmore, Okla,
His llnal \\ords to Pullman friends
sw i re expi c ssiona of appreclai lon for
the regard shown him by the buel
m men of Pullman and the Btu
dents and faculty. "J will a! ■
it keen interesl in Pullman and
,the state College," he said, "and am
proud to fee] that l am lei i
y friends "
tl is known thai Coach Welch al
'. era! att racl vi coai hing
■ of t hem in ■<. but
likely that he will quit the
coaching game and enter the practice
ol I w, tor which he was fitted at
DickeTi.son Law School following his
graduation from Carlisle. He is
fond of the west, and even though he
should practice law, it would not be
surprising to find him located in one
of the wi tern states,
Kosenthal ;i IV- Utility
l )r. Boli Ro enthal, assistant to
Coach Andy Smith at California Uni
versity, i - being prominent ly men
tioned in local football gossip as a
probable successor to Coach Welch.
Whether or not Dr. Rosenthal would
Ider the Pullman job as problem
■ at leal, and ihe members of the at h
lei ie council are non commit tal as to
the probability of the council making
him .1 definite offer Dr. Ronenthal
is a practicing physician and ii would
likely take a tempting offer to cause
j him to leave his pract Ice to tutor the
Dr. Rosentha 1 Is r di riple of the
Warner style of play, which ha
taughl at the State College , Ince Ihe
advent of Coach l.nin slur Dietz in
191 a. According lo college athlet Ie
heads, an effort will be made i., i
cure a coach vei sed In this stj le of
| play. While several such coaches
have been unofficially mentioned, the
athletic board has no definite line on
any of them at the present time. It
is expected that Athletic Director J.
F Bohler may have an Interesting re
port on the situation when he returns
from his trip to California, where he
will visit the several college centers
By Floyd L. Smith. Sporting Editor,
Spokesman-Re\ lew
After serving Washington State
('"! i! football coach for four
year Gustavlus A. Welch has re
signed. The Cougars have lost a
man, a sportsman, ami a leader who
I has won merited esteem throughout
the Northwest. His team;, have won
15 of 24 Intercollegiate games. With
j a green squad with which to work In
I 922, he lias laid the foundation for
'"■' ter things I r>r his unnamed sue
■■"• Wi ich may h ,r,, w. S. C
but the memory of his inspiring in-
I fluence will linger long in Cougar
| town. H,. has Instilled the spirit of
fighting to win, but fighting to win
clean. He has taught his proteges
that W. S. C, will be represented on
its athletic team by gentlemen and
gentlemen only. Hence Washln
State has added further laurels and
gained greater recognition in its vic
tories as well as In it- defeats.
Through the veins of Gus Welch
flows the red blood of Indian an
cestors. But he', the whitest sports
man who has trod a northwest grid-
Iron.
STATE COLLEGE IMIUo
STATION \()\\ OPERATING
"X F A i:.'- the State College radio
broadcasting station, is now in op
eration, and sending material from
the college through the whole North
wesi regularly. This station equip.
ment, which would have cos! in the
open market not less than $15,000,
has been made possible chiefly by
the efforts of the student body and
friends of the college. All the work
of assembling parts of the equipment
and of making those parts which
could he made here has been done
by Dean Carpenter, Professor liana
and students and a isistani -.
The Btation hag an effective send
ing radius of 500 miles, which mi
that the whole Btate of Washington,
from North Head at the mouth of the
Columbia, to Cape Hattery, the little
hamlet <m Boundary, next to the
British line In Stevens county or the
most remote point among the Asotin
hills can hear lectures on agricul
ture, engineering problems, cultural
Information, scientific data and vo
cal or Instrumental music from the
state College
President Holland has appointed
the following as members of the fac
ulty committee on radio broad.
inn: Dr. P. F. Nalder, director of
general college extension, chairman;
Dean E. C. Johnson of the college of
agriculture, Director s, r Nelson of
the agricultural extension service,
Dean H. v. Carpenter of the college
of engineering, Dean Florence Hai ri
son of the college of home econom
ios. he;,n Herbert Kibmrougfa of the
school of music and fine aits, and
Professor H. \v. Cordell, head of the
department of economics. Dean
Carpenter has been appomied secre
tary of the committee, which is hold
ing weekly meetings to derelop poll-
<Us WELCH
cfog hi operation and to direct tht
preparation of program!.
"Our radio outfit hat enoftnutti
bilitii i for Increasing the pr»< -
tical usefulness <>f the State Col
lege." said Dr. P. P. Naldi ' We
members of the committee are Im
ed chiefly by the slee ol our Job.
There is an enormoui amount of ma
terial available, which can be put.
in shape suitable for broadcasting.
As tar as I hai been iMe to ana-
Ij, c ihe programs may i c I <■<
of brief lectures on agricultural, sci
entific, technical, economic, business
educatlonal subji cts. .Music of
.1 high order will also ilarly
Interspersed. The question ol! fre
quency of programs h i nol yel I
fully determined, it is obvious that
our programs will have to come at
gfij i%/ltistoCTal find that we are
P|: I oj me overstocked on Com
»^tnin^ T nit? £! ate * and
jjp|;g| O after the New Year
TUift^^^P have left at
Ww ml if Reduction
JV' i^L-i 1-J^ For one week only
Phone 24 Good Goods Only
\ I
8 We Wish All Our Friends §
A Happy and Prosperous &
fi New Year i
I (P I-
I I
R The Eledric Supply Store i
The Eledtric Supply Store U
\J \V. E. DAIRD, Mgr. *%
I §
Sincerely We Wish You and
Yours a Very Happy
and Prosperous
New Year 4
PULLMAN TIRE SHOP
Corner Main and Grand Phone 855
'•><<>>. December 2f>, 1022 V
specified tmea each week. With
this si)le nd ,i equipment at hand and
our fine fidd in the Northwest to be
covered, there is every reason that
through the radio the value of the
I .State Colii •! to the people of the
I state of Washington can be greatly
enhanced. The fact that the radio
'MlMlt is mainly the gif( of students
and fri(>,i s of the college and has
not hen laid for my money raised by
taxation/ makes its worth perhaps
more significant."
The Hrßl step to tak« m putting a
1 ■"''" •) a good business hasia
! lake m annual Inventory.
A meal dressed with chatting and
•led with laughter is halt
digest.■(!.
