#### Question

# Help me I give 10 pts please! I spent 3 days on this?

http://www.webassign.net/sercp/p20-58.gif

The square loop in the figure below is made of wires with a total series resistance of 10 ohms . It is placed in a uniform 0.100 T magnetic field directed perpendicular into the plane of the paper. The loop, which is hinged at each corner, is pulled as shown until the separation between points A and B is 3 m. If this process takes 0.100 s, what is the magnitude and direction of the average current generated in the loop?

Please explain your steps too!

#### Answer

Here are the three concepts you need.

The magnetic flux is equal to the magnetic field times the area the field passes through flux = B*A

The induced EMF is equal to the change in flux over time EMF = d(flux)/dt

The induced current is equal to the EMF divided by the resistance. I = EMF/R

Since the B field is constant you therefor have to figure out dA/dt. How is the area changing with time. I think it is a simple as Afinal - Ainitial divided by 0.1 s.

Now EMF = B*(Afinal - Ainitial)/0.1 s

Divide that by the resistance and you should have your current.