Insight 2010 questions 3-5 of magnetism

[cameron_15]

Basically, What the hell is going on with this setup?

The bundle of rods being passed over the metal rails, I sort of see how they are getting area's but would someone care to explain?

I don't have the exam on my PC so I can't upload the question, sorry.


Thanks for any help.

[Whatlol]

basically a peice of metal is being slid over two peices of metal which can conduct electricity. This is just like having a circuit, the current induced in the metal will flow through the rails and into the light bulb.

The first question relates to induced current and emf, as a result of changing the magnetic field and consequently a change in flux occurs.

although... now that i read over question 4, i cant see why there will be any EMF induced since there should be no change in flux.

[cameron_15]

I understand the change in flux, what I don't understand is why the area is .3 x .15...

The metal rods aren't .15 meters wide... Am I missing something?

[d-ea-6]

No, I agree with you. The width of that 15cm arrow doesn't seem to correspond to the width of the rails at all.

Seriously, the people who QC'ed this exam must be retarded; the sheer number of errors that are in the solutions is just ridiculous.

[cameron_15]

No, I agree with you. The width of that 15cm arrow doesn't seem to correspond to the width of the rails at all.

Seriously, the people who QC'ed this exam must be retarded; the sheer number of errors that are in the solutions is just ridiculous.

I know!

question 17, 30/.2 = 600! It equals 150, But this is an 'alternate solution'. Huh?

I'm not too fussed, it's a pretty badly worded exam. VCAA would never give us anything that vague.

[itolduso]

insight has sent out the amended version, ask your teachers