successone motors n generators (1 Viewer)

[stef.]

for q22b... as you reduce the mag field..isnt that like pulling a north pole away from the bottom (ie. theres a north pole on hte other side of that loop and your pullin it away) so that means by Mr. Lenz that a south pole will be induced on the under-side of hte loop..so that means if you look from the bottom (other side of loop) that current should flow clockwise...so Y should b positive?

someone clear me up

nb: answer says X is positive

 

[helper]

Stephanie I am assuming you are talking about the question with the coil in the mag field.

Only look at one side of the coil or you start getting confused.

You are reducing the magnetic field in the middle, so you want to stop the reduction, so you want to form a magnetic field coming out of the page, which from the top the positive charges are going anti-clockwise.

That is the same as what you have.

Then the confusion comes in.
This is not a circuit, it is a single piece of wire, so as the charges move, they will go as far as they can. The positives will move towards X as that is where your current is going to. This means the positives acculmulate their and the negatives accumulate at X, producing the charge at X and Y.

In the exam don't talk about positives moving like I did, talk about it terms of electrons moving, producing a negative charge at Y and lack of negatives at X result in it being positive.

 

[ifsonotso_100]

hey stephanie, would u poss be able to scan hsc 04 solutions.

 

[stef.]

sorry..ive got older version...no 04 paper