Lab 1 FaradaysExpt

7/30/2019 Lab 1 FaradaysExpt

1/9

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FaradaysLawExperiment Wednesday,February13,2013 1

CoverSheetforElectromagneticTheoryLaboratory

AssignmentI

Studentsshould

complete

the

Laboratory

preparation,

and

the

laboratory,

in

pairs

Family Name First Name Student Number .

Family Name First Name Student Number .

Date

Declaration

and

(please sign) and

hereby declare that the attached work is wholly our own work and we have equally contributed toit. We recognize that severe penalties, including suspension, apply for plagiarism - see plagiarismlink at:

http://students.curtin.edu.au/administration/responsibilities.cfm

Due:

Place:

Value:ThisAssignmentisworth10%ofthefinalmarkinElectromagneticTheory310.

Style: Pleasestructureyourreportcarefully highlightimportantresults

A coherent consisting of appropriate theoretical results & derivations and experimentalresults,aswellasanappropriatediscussionofsuchresults,isrequired.

Clearlydemarcatedifferentsectionsofyourreportandclearlyhighlightimportantresults. Preferablytheassignmentshouldbeneatlyhandwritten(usingapen)ononesideofapage

only.

Note: Penaltiesapplyforlatesubmission.Laboratoryattendanceismandatory.

Marks may be deducted for an experimental setup that does not conform tospecifications.

LABORATORYSESSIONS

LaboratorySessions

will

be

conducted

in

room

204.229

during

teaching

weeks

9:

Tues:

15

17

pm.


2/9

_________

FaradaysL

Labo

1.1 Pre-1.1.1 Re1.1.2 Co

(a)An(b)Wr

1.2 PrepThe g

experimen

1.3 IntrThe

case (/t

and (4) ar

with the c

and fourth

and dyna

system, a t

varying el

and lectur

Tabl

_________

awExperim

ratory

ab Assig

d lecture n

plete Part

swer questi

ite an expe

aration

oal is for y

tal setup as

duction

axwells e

=0), equati

used to st

upling tha

equation i

ic fields.

ime-varyin

ctric field

notes.

1: Maxw

________

nt

andAs

ment:

otes (Wee

A in your

ons (Q1-Q

imental pr

nd Labo

u to under

discussed i

nd Bac

quations b

ons (1) and

dy the ma

t exists bet

Table 1.

he same i

magnetic

generates

lls equati

_________

Wednesd

signm

Far

5/6), this

eport befo

): Part A

cedure.

atory G

tand Farad

n followin

ground

th in diffe

(2) are us

netic phen

ween the e

quation (1)

true for e

field gener

magnetic f

ns in both

_________

ay,Februar

ntfor

days

ocument a

e coming t

al:

ays law a

sections.

heory:

ential and

d to study

omena of t

ectric and

is known

uation (3)

ates electri

elds (Amp

differenti

_________

13,2013

Electr

Law

d referenc

o lab:

d to verify

integral for

the electri

he system.

magnetic f

s Gauss la

(Gauss la

field (Far

eres law).

l and inte

_________

magn

book.

its validity

m are sho

al phenom

In dynamic

elds, as ex

and equa

for magn

days law)

The details

ral form.

_________

ticTh

through th

n in Table

ena, and e

case, we

pressed by

ly valid fo

tism). In t

and, simil

are in refe

(1)

(2)

(3)

(4)

______

2

ory

1. In static

uations (3)

ave to deal

the second

both static

e dynamic

rly, a time-

rence boo


3/9

_________

FaradaysL

Farad

motor, tra

crosstalk

varying cu

this circuit

_________

awExperim

ays law o

sformers.

ne circuit

rrent next

s as shown

________

nt

electroma

aradays l

introduces

o a circuit

in Fig. 1.

Fig. 1. Exa

_________

Wednesd

netic indu

w can be

on another

as illustrat

ple of a ci

_________

ay,Februar

ction is th

applied to

. For exa

ed below t

cuit demon

_________

13,2013

basis of t

other areas

ple, if ther

en an un

strating Fa

_________

e electric

such as de

e is a con

anted volt

adays law

_________

generator,

termining

uctor carr

ge will be

.

______

3

the electric

he level o

ing a time

induced i


4/9

_________

FaradaysL

Consid

in the con

From Fara

The left

electroma

Fig.2 Deficond

Now as pe

potential a

_________

awExperim

r the geo

uctor is po

days law:

cE

and side t

netic force

ition of thector carryi

r right han

t airgap (Ve

________

nt

etry of a cl

sitive and i

s tdl

B

erm of eq

(emf).

potential ang a positiv

rule, the d

mf) will be

_________

Wednesd

ose loop w

creasing.

s dsB

sdt

dd s

ation (6)

nd the diree current,

irection of

ositive.

I>0,

_________

ay,Februar

th air gap

s we kno

d

dd sB

is the volt

tion of elehich is inc

will be i

Iincreasing

_________

13,2013

s shown i

, the magn

emfV

age over t

tric field aeasing.

to the page

_________

Fig.2, wh

tic flux is

(5)

e loop w

ross an air

. With incr

_________

re the curr

defined as:

(6)

ich is als

gap in the

asing curr

______

4

ent flowing

called a

icinity of

ntI, the


5/9

_________

FaradaysL

Answer th

Part A:

Q1: What

is pos

potenB an

Q2: What

curre

Q3: Supp

curre

the s

phasthan

poten

Airgap

Q4: (a) T

show

net fl

each

(b):

(c):

_________

awExperim

e following

will be th

itive and d

tial Airgapthe direct

will be th

nt is not c

se the cur

nt. It is re

me freque

of the potne) when

tial Airgap

cos(0 t

e structur

in the fig

x flowing

oop first.)

xplain wh

hat will h

________

nt

questions:

direction

ecreasing?

hen the cion of the

potential

anging wi

rent is sin

sonable to

ncy, i.e. A

ntial Airgthe potenti

as the ma

) .

e of a twis

ure. If suc

through l

Fig.3 : G

twisted

ppen if y

_________

Wednesd

of B and t

What will

rrent is notential

Airgap and

h time)?

soidal, i.e.

assume th

cos0rgap

p. Using Fal Airgap is

ximum am

ed wire pa

a wire is

op 1 and l

ometry of

ires will b

u use para

_________

ay,Februar

e directio

be the dir

gative an

irgap when

the directi

cos(0II

at the ind

)( t ,

radays L0; (b) the

plitude 0

ir is show

ubject to

op 2? (Hi

wisted wir

used in y

llel wires i

_________

13,2013

of the po

ction of B

increasinthe curren

n of B wh

)t , wher

ced poten

here 0 is

ay, determoments (

. (c) Now d

in Fig. 3.

niform m

t: Determ

e pair of pr

ur experi

nstead of t

_________

ential Airg

and the di

? What wt is negativ

n static c

0I is the

ial Airgap i

the magni

ine: (a) thore than

etermine t

he directi

gnetic fiel

ne the dir

blem Q3.

ent (refe

isted wir

_________

ap when th

rection of

ill be the de and dec

rrent is u

magnitude

also sinus

ude and

momentsone) when

he phase

on of curr

d, what wi

ction of s

to section

s?

______

5

current

he

irection ofeasing?

ed (i.e.

of the

oidal with

is the

(morethe

in

nt is

ll be the

rface in

1.4)?


6/9

_________

FaradaysL

1.4 Exp

The e

the labora

pairs will

Fig.4. Ex

_________

awExperim

rimental

xperimenta

ory you w

e soldered

erimental

________

nt

Setup:

l setup and

ll be give

with the 5

setup for

_________

Wednesd

the layout

two twist

Ohm resis

easuring

Fig.5. E

_________

ay,Februar

ith dimen

d wire pai

tor inserted

otential a

periment

_________

13,2013

ion details

rs and a 5

, as shown

ross the a

l layout.

_________

are shown

Ohm resi

n Figures.

r gap of lo

_________

in Fig. 4 a

stor. The t

op1 (loop

______

6

d Fig. 5. I

isted wire

).


7/9

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In this experiment, a sinusoidal current I is fed through the current loop, which is the outermost

loop (see Fig. 4). The tasks are: (1) Observe the induced EMFs in the other two loops, loop1 and

loop2; (2) Analyze the observed results and verify Faradays Law.

It is recommended that the loop current be such that

0.052 (A) (7)

and that the frequency range of 10kHz to 1MHz be used.

1.5 Laboratory equipment requires: HP 54600B Oscilloscope or Agilent equivalent HP 33120 Signal Generator 2 x 0.8m twisted wire pair connected to a standard BNC connector at one end only 1 x T connector (male-female-male) 56 Ohm resistor Soldering Iron and solder, Soldering goggles, Extraction fan Wire cutters and Pliers and soldering setup. User manuals will be available in the lab.

1.6 References:Most standard books on Electromagnetics cover Electromagnetic induction and Faradays law.

1. Ulaby et al, Engineering Electromagnetics, Pearson Publication.2. Lecture notes Week 5/6


8/9

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1.7 Assignment:Part B: (Experiment):

The experimental setup and the layout are shown in Fig 4-5. Please make sure that the connections

are as shown in figures.

Q5:

Measure the potentials and phase shift (between driving current and the measured potential) across

the air gaps of loop 1 and loop 2 and tabulate the results in following tables. For your reference

expected value of the potential at 20 kHz for loop 1 is shown in the table.

Table A: Loop 1:

Freq. (kHz) Measured (mv) Phase shift (deg)10

20 About 10.6

50

100

200

500

1000


9/9

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Table B: Loop 2:

Freq. (kHz) Measured (mv) Phase shift (deg)

1020

50

100

200

500

1000

Q6:

Draw time domain waveforms forI andAirgap for loop 1 and loop 2?

Q7:

Consider the two rectangular loops (loop 1 and loop 2, refer to Fig.5) in your experiment.

Theoretically, using Faradays Law, (a) Determine which of the following two is larger, 2VLoop1 or

VLoop2 , where VLoop1 andVLoop2 are the EMF induced in Loop1 and Loop2. (Hint: The area of loop 2

is a portion of the area of loop 1.) (b) What phase shift is expected? Why? Are your experimental

results consistent with your analysis here?

Q8:

Write one paragraph describing what you learned from this experiment?

1.8 LAB write-up:

The lab report most have 2 parts (Part A and Part B).

1. Answer questions (Q1-Q4) and the experiment procedure: (Part A) before coming to lab.2. Fill up the cover sheet.3. Answer questions (Q5-Q8): Part B

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