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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Physics => Topic started by: tony3272 on August 08, 2011, 04:24:26 pm

Title: Lenz's Law
Post by: tony3272 on August 08, 2011, 04:24:26 pm
Hey guys. I just had my physics sac last week and we had this question on it. It's from checkpoints somewhere.
But anywhoo, most of my friends and I selected choice A, saying that they're all wrong but A is the 'most correct'. The answer is D however, and our teacher isn't listening to our reasoning at all. He says that "because A is so incorrect, D is the answer".

What do you guys think?
Title: Re: Lenz's Law
Post by: Lasercookie on August 08, 2011, 05:23:21 pm
I would say that D is incorrect.

It's saying that electric current is induced by electric current (could be considered true in some situations).  Take a look at this: http://www.youtube.com/watch?v=hajIIGHPeuU. Specifically experiment 1, it shows a solenoid. The magnetic flux is changed and a current is induced. The solenoid didn't have a current passing through it before the flux changed. It was due to the flux change that the current was induced.

Key words: flux, change.
A change in flux is one of the requirements to induce current, field whatever.

Option A is the only one that mentions that. So for that reason I would say that 'A' is the correct answer.