• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

induction motor or cooktop? (1 Viewer)

kunny funt

Large Member
Joined
Oct 29, 2004
Messages
153
Gender
Male
HSC
2004
what the hell was it???

i changed my answer so many tyms i cant remember what i ended up with ....
 

speersy

Member
Joined
Feb 8, 2004
Messages
294
Location
new south wales south coast
Gender
Undisclosed
HSC
N/A
in the exam i thought this was a band 2 answer so i did not hesitate to put induction cooktop, however pretty sure it is wrong now though,lol
 

gordo

Resident Jew
Joined
Feb 5, 2004
Messages
2,352
Location
bondi, sydney
Gender
Male
HSC
2004
i did cooktop
the question was about inducing eddy currents for a practical purpose
i think cooktop takes the cake over an induction motor which works completely differently in terms of being more complex
 

BillyMak

Silent majority
Joined
Aug 20, 2004
Messages
443
Location
Randwick
Gender
Male
HSC
2004
Induction motor, although a lot of people will say otherwise.
 

BillyMak

Silent majority
Joined
Aug 20, 2004
Messages
443
Location
Randwick
Gender
Male
HSC
2004
An induction motor spins because of the magnetic fields associated with eddy currents interacting with the permanent magnetic field.
 

gordo

Resident Jew
Joined
Feb 5, 2004
Messages
2,352
Location
bondi, sydney
Gender
Male
HSC
2004
hmm i just read the question again

i think the electro magnet is being used to spin the train wheel the other way not affect the track line
 

gordo

Resident Jew
Joined
Feb 5, 2004
Messages
2,352
Location
bondi, sydney
Gender
Male
HSC
2004
although that doesn't work because the electro magnet is parallel with the wheel
 

BillyMak

Silent majority
Joined
Aug 20, 2004
Messages
443
Location
Randwick
Gender
Male
HSC
2004
It would be with the wheel. The question refers to electromagnetic braking, and it works by inducing eddy currents in the wheel of the train and slowing it down.

An induction motor works by a dynamic magnetic field inducing eddy currents in the rotor thinger, making it spin.
 

gordo

Resident Jew
Joined
Feb 5, 2004
Messages
2,352
Location
bondi, sydney
Gender
Male
HSC
2004
but the wheel is moving paralell with the electric field, its not gonna cut the flux lines at all
 

gordo

Resident Jew
Joined
Feb 5, 2004
Messages
2,352
Location
bondi, sydney
Gender
Male
HSC
2004
albeit regardless of that its obviously inducing eddy currents or cooktop would be wrong to

grrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr
 

BillyMak

Silent majority
Joined
Aug 20, 2004
Messages
443
Location
Randwick
Gender
Male
HSC
2004
Yeh.... I dunno.

I've had enough thinking about physics now. There's really no point, considering we can't change our answers and you can only get depressed by picking out what you got wrong.
 

Xayma

Lacking creativity
Joined
Sep 6, 2003
Messages
5,953
Gender
Undisclosed
HSC
N/A
Take a point on the wheel and you will see that it moves further away creating a change in flux.

I looked at it as the following energy transformations:
Kinetic --> Electrical --> Heat

I put cooktop but Im over it.
It has:
Electrical --> Heat

But an induction motor has

Electrical --> Kinetic
 

boz

CEO
Joined
Feb 2, 2004
Messages
61
Location
Wollongong
Gender
Female
HSC
2006
the effect of the magnet on the wheel is minimal. The track is being most affected as it is constantly cutting flux lines, inducing currents in the track to oppose the motion of the train.

I put induction cooktop.
Is it possible that they will accept both answers?
 

whenever2gether

New Member
Joined
Feb 21, 2004
Messages
25
Gender
Male
HSC
2004
Ohohoho

i put induction motor!

not only they said 'law of conservation of energy'

also we have to consider lenz's law

lenz's law is applied in both induction motor and em braking

and also cooktop=eddy currents


lol

thats wat i thought

correct me if im wrong
 

ematouk

New Member
Joined
Mar 5, 2004
Messages
20
The answer is clearly evident either way (cooktop or motor)

I just thought cooktop, purpose is for heating (unlike question)... while motor is used for change in kinetic energy (like question).

either way the question can be argued and here is what i think they'll do... I think they will do the same thing they did for q5 in the 2003 (accepted both B & D) paper and accept both answers.
 

joshhopp

New Member
Joined
Mar 22, 2004
Messages
28
Location
griffith
Gender
Male
HSC
2004
all i can say is that its pretty mean if the answer is not cooktop: the cooktop and electromagnetic braking are studies side by side in all textbooks.
 

blackbunny

Member
Joined
Mar 17, 2004
Messages
466
Gender
Male
HSC
2004
you stupid fucks
its C u sad monkeys couple of hints its C... the train is moving so does the induction motor ,,, im sure u all did this investigation on the induction motors caz when the magnetic flux changes the motor spins to opose that by lenz law (energy conservation)

what the fuck does an induction cooktop has to do with law of energy basicly its just that currents are induced in the cooktop so what if they are induced in the direction to opose that makes no difference but for induction motor it does
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top