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Technology Enabled Active Learning (TEAL)

Learning without Barriers / Technology without Borders

Symposium

December 2, 2006 John Belcher, Peter Dourmashkin

Physics DepartmentMIT

Creative Commons Attribution-Share Alike 2.5 License

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Learning Objectives of TEAL

Create an engaging and technologically enabled active learning environment

Move away from passive lecture/recitation

format

Incorporate hands-on experiments

Enhance conceptual understanding

Enhance problem-solving ability

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Broader Educational Learning Objectives

Develop communication skills in core sciences

Develop collaborative learning

Create an environment conducive to learning

and teaching

Develop new teaching/learning resources

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Desktop ExperimentsPut lecture demos into students hands

Groups of three students take data in class using LabView software.

Introduction to experimentation

Integration of concepts and experience

Graphical representation of physics concepts

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Website

web.mit.edu/8.01t/www web.mit.edu/8.02t/www

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A Sample 8.02 TEAL Class

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Thanks to the MIT first year students in 8.02 this term who are joining us today:

Nicole Bieber Christopher CosmidesMark BarineauNeeharika Bhartiya

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8.02 Class 31: OutlineWednesday Nov 29, 2006

Hour 1:

Generating Electromagnetic Waves

Plane EM Waves

Electric Dipole EM Waves

Hour 2:

Experiment 8: Microwaves generated by the spark gap antenna

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Clicker Question:Your E&M Background

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My Last Course in E&M Was In

Hig

h Sch

ool

Colle

ge

Gra

d Sch

ool

Nev

er h

ad o

ne

100%

0%0%0%

1. High School

2. College

3. Grad School

4. Never had one

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Clicker Question:Baseline E&M Knowledge

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The earth’s magnetic field in this room is:

Most

ly v

ertic

al a

nd p

o...

Most

ly h

orizon

tal a

n...

Most

ly v

ertic

al a

nd p

o...

Most

ly h

orizon

tal a

n...

0%

100%

0%0%

1. Mostly vertical and pointing down

2. Mostly horizontal and pointing north

3. Mostly vertical and pointing up

4. Mostly horizontal and pointing south

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The earth’s magnetic field in this room is:

Most

ly v

ertic

al a

nd p

o...

Most

ly h

orizon

tal a

n...

Most

ly v

ertic

al a

nd p

o...

Most

ly h

orizon

tal a

n...

0% 0%0%

100%1. Mostly vertical and pointing downward

2. Mostly horizontal and pointing north

3. Mostly vertical and pointing upward

4. Mostly horizontal and pointing south

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Answer: 1. The earth’s magnetic field in this room is mostly vertical and pointing downward

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Clicker Question:Sophisticated E&M Knowledge

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As we move our receiving antenna around the spark gap antenna as shown , we see

1. More power at A

2. More power at B

3. Same power at A & B

4. Do not know

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Review: Electromagnetic Radiation

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Recall Electromagnetic Radiation: Plane Waves

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Properties of EM Waves

8

0 0

13 10

mv c

s

0

0

EEv

B B

Travel (through vacuum) with speed of light

At every point in the wave and any instant of time, E and B are in phase with one another, with

E and B fields perpendicular to one another, and to the direction of propagation (they are transverse):

Direction of propagation = Direction of E B

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How Do You Generate Plane Electromagnetic Radiation?

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Shake a Sheet of Charge

Link

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2) If sheet position is

What is B(x,t)?

What is E(x,t)? What Direction?

Group Problem: B Field GenerationSheet (blue) has uniform charge density Starting time T ago pulled down at velocity v

1) What is B field?(HINT: Change drawing perspective)

0( ) siny t y tsheet

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Plane waves are simple but not what we usually see

How Do You Generate What We Usually See: Electric Dipole Electromagnetic

Waves?

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Generating Electric Dipole Radiation Applet

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How Do You Shake a Charge?Spark Gap Antenna

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Spark Gap Antenna

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Clicker Question:Sophisticated E&M Knowledge

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As we move our receiving antenna around the spark gap antenna as shown , we see

More

power

at A

More

power

at B

Sam

e po

wer

at A

& B

Do n

ot know

0%

50%50%

0%

1. More power at A

2. More power at B

3. Same power at A & B

4. Do not know

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Answer: 2. Maximum power at A.The electric field pattern from the spark gap

antenna is shown. We get maximum power when the line from the transmitter to the receiver is perpendicular to the direction of the antenna (at A). We get (in principle) zero power when the line from the transmitter to the receiver lies along the direction of the antenna (at B).

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Experiment 8Spark Gap Generator:

An LC Oscillator

LC

1 12.5 GHz

2f

LC

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Our spark gap antenna

6 12 4(4.5 10 )(33 10 F) 1.5 10 sτ RC

rad

1

4

cf

T l

103 10 cm/s

12.4cm

1) Charge gap (RC)

2) Breakdown! (LC)

92.4 10 Hz 2.4GHz 3) Repeat

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Spark Gap Antenna

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Spark Gap Antenna

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What Lies AheadFocus on teacher training Continued development of Teaching/Learning

resources Introduction of new communication devices into

classroomRefine experiments with a shift towards Inquiry-

Based experimentsDevelopment of tabletop demosPublication of MIT 8.01/8.02 Course Notes