A few Electromagnetic questions

[Plasma]

A:

Homework Statement

http://i12.photobucket.com/albums/a234/Xuxyz/battery.jpg"

(a) i. Using the information in the graph, determine the potential difference Vo across the resistor immediately after the switch is closed.

Homework Equations

Vo = Io * R

The Attempt at a Solution

I don't know how to find Io using the grap, because as you can see from my link, it doesn't intersect at a specific point.

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B:

Homework Statement

http://i12.photobucket.com/albums/a234/Xuxyz/04-08-2007015444PM.jpg"

I only need help on part f

Homework Equations

I don't know.

The Attempt at a Solution

None, sorry. I don't have a clue.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

C:

Homework Statement

http://i12.photobucket.com/albums/a234/Xuxyz/04-08-2007020007PM.jpg"

Only part D

Homework Equations

EMF = vBD
I = vBD / R

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I know this is a lot, but I would appreciate any and all help.

 

[robb_]

For number 1, it looks to me like the graph shows a current of about 9.5 A??

*For your second question, what is happening as the loop is moving away from the wire?*

 

[Plasma]

For number 1, it looks to me like the graph shows a current of about 9.5 A??

It's actually slightly below 9.5 A

*For your second question, what is happening as the loop is moving away from the wire?*

The Magnetic field strength is decreasing.

 

[robb_]

1. Okay, slightly less than 9.5 A.
2. So if the field strength is decreasing, what about the flux?

 

[Plasma]

1. Okay, slightly less than 9.5 A.

But I need an actual number for the equation to work.

2. So if the field strength is decreasing, what about the flux?

The flux would be decreasing, too?

 

[robb_]

1. You must use your eyeball.
2. Yes, the flux is decreasing, good. From this, can you tell me which direction is the induced current.

 

[Plasma]

2. Yes, the flux is decreasing, good. From this, can you tell me which direction is the induced current.

I don't need to know the direction of the current, I need to figure out what it's equal to.

 

[robb_]

Well, I thought you might want to learn what is happening.
What does a changing flux produce?

 

[Plasma]

The induced current is counterclockwise.

 

[robb_]

Very good.

 

[Plasma]

But what about it's value?

 

[robb_]

A changing flux induces an emf around the circuit. Find out the relationship between this emf and other physical quantities.

 

[Plasma]

EMF = the derivative of flux vs time.

 

[robb_]

So can you quantify how the flux changes?