11 UOL Ireland Induction Hobs

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The presentation from Ireland

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INDUCTION HOBSINDUCT YOUR KITCHEN INTO THE HALL OF EFFICIENCY

WHAT WE KNEW

INDUCTION COOKING HEATS A

COOKING VESSEL BY A

CURRENT INDUCED BY

MAGNETISM. SOME OF US

HAD AN IDEA ABOUT WHAT

THIS MEANT.

OBJECTIVES

(1) INVESTIGATE:

WHERE THE POWER TO THE HOB COMES FROM.

HOW INDUCTION WORKS.

HEATING EFFECT OF A CURRENT.

(2) DETERMINE:

COMPARISONS OF INDUCTION HOBS TO STANDARD

ELECTRIC COOKERS.

PRACTICALITIES OF INDUCTION HOBS.

DEFINITIONS

ELECTROMAGNETISM

This is the interaction of electrical

currents and magnetic fields.

MAGNETIC FLUX

This is the amount of magnetic field

passing through a particular area.

DEFINITIONS

LENZ’S LAW

This states that the induced current is generated so as to oppose

the change which causes it.

FARADAY’S LAW

This states that the induced voltage is proportional to the rate of

change of magnetic flux.

STRUCTURE

• IN AN INDUCTION COOKER, A COIL OF COPPER

WIRE IS PLACED UNDER THE CERAMIC TOP PLATE.

• THERE IS A MAGNETIC SOURCE (INDUCTION) AND

A SUPPLY (MAINS ELECTRICAL SUPPLY).

• THE MAGNETIC FIELD INDUCES A CURRENT IN THE

UTENSIL WHICH GENERATES HEAT AND

THEREFORE COOKS THE FOOD.

EXPERIMENT 1:

HOW INDUCTION WORKS

WHAT WE USED: 2 COILS OF COPPER WIRE, A

GALVANOMETER, POWER SOURCE AND MAGNETS.

THE CURRENT PASSED THROUGH THE COPPER

WIRE CREATES AN ALTERNATING MAGNETIC FIELD.

EXPERIMENT 2:

THE HEATING EFFECT

OF A CURRENT

• THE PURPOSE OF THIS EXPERIMENT WAS TO TEST THE

FORM OF HEATING KNOWN AS "JOULE HEATING".

• WHILE DOING THIS TEST, WE SLOWLY INCREASED THE

AMOUNT OF ELECTRICITY PASSING THROUGH A COPPER

WIRE IN A CUP OF WATER.

18

23

28

33

38

43

0 1 2 3 4 5Te

mp

era

ture

C

°(C

els

ius)

Time (Minutes)

0.5A

1A

3A

5A

Heating Effect of a Current

RESEARCH ON PRACTICALITIES

➢ ONLY ABOUT 16% OF

THE INDUCTION HOB IS

HEATED (CENTRE).

➢ THE CHANGE IN HEAT

IS INSTANT.

➢ POTS MADE FROM A

CERTAIN MATERIAL

ARE NEEDED TO COOK

WITH INDUCTION.

➢ IT MAY HARM YOUR

IMMUNE SYSTEM.

➢Websites➢ http://theinductionsite.

com/

➢ http://theinductionsele

ct.com/

➢ http://europace.oxfordj

ournals.org/

➢Practical➢ Induction Hob

➢ Experiments

Energy

Efficiency

65%

35%

Standard Electric Cooker

84%

Induction Hob

Used

Un-used

16%

Data Collected and Comparisons

𝑝𝑜𝑤𝑒𝑟 =𝑒𝑛𝑒𝑟𝑔𝑦

𝑡𝑖𝑚𝑒

𝑒𝑛𝑒𝑟𝑔𝑦 = 𝑚𝑐Δ𝜃

𝑚 = 200g 𝑐 = 4200 𝐽𝑘𝑔−1𝐾−1 Δ𝜃 = 53K

0.2𝑘𝑔 𝑥 4200𝐽𝑘𝑔−1𝐾−1 𝑥 53𝐾 = 44,520𝐽

Standard Hot Plate took 285.92 seconds = 44,520

285.92= 155.71𝑊

Data Collected and Comparisons

Induction Hob took 45.47 seconds = 44,520

45.47= 979.11𝑊

979.11

155.71= 6.3

Hot Plate = 1500W Induction Hob = 2100W

2100

1500=7

5= 1.4

The Induction Hob is 6.3 times faster and 1.4 times more powerful!

DISCUSSIONS

• ONCE WE FINISHED WE SHARED ALL OF THE INFORMATION

THAT EACH OF US FOUND IN OUR SEPARATE INQUIRIES.

• THE TOPICS WERE EXPLAINED TO THE OTHER GROUP

MEMBERS AROUND THE TABLE.

• WE PUT ALL OF THE INFORMATION TOGETHER AND

DISCUSSED THE RESULTS.

• WE ALSO MADE OUT A SELECTION OF LEAFLETS

EXPLAINING THE IMPORTANT INFORMATION.

CONCLUSION

• IN THE END WE CAME TO THE CONCLUSION ON HOW

AN INDUCTION HOB WORKS.

• WE CONCLUDED THAT THE TEMPERATURE AT WHICH

IT COOKS DEPENDS ON THE SIZE OF THE CURRENT, THE DURATION OF THE CURRENT AND THE AMOUNT

OF FOOD IT'S COOKING.

OUR THOUGHTS

ON SCIENTIFIC INQUIRY

1. WE FOUND THAT SCIENTIFIC INQUIRY MADE IT A LOT

EASIER TO LEARN ABOUT INDUCTION HOBS.

2. COMING UP WITH OUR OWN WAYS TO

DETERMINE/PROVE THAT A HYPOTHESIS IS TRUTHFUL

WAS A LOT MORE FUN THAN SITTING AT A DESK AND

TAKING DOWN NOTES.