HELP Elctromagnetic Questions

[rukawa0929]

HELP ! Elctromagnetic Questions

Ok I need to solve for Resistance, but itseems like I don't have enough info
Here's my question :

The rectangular wire loop has dimensions of 4.0cm by 3.0cm. Moving at constant
speed, the loop completely exits the 0.14T uniform magnetic field in 0.12 seconds.
The wire has a radius of 0.40mm and a resistivity of 2.15 x 10^-8 Ohm x m .

Determine:

A) the resistance of the wire

Can you please help me with this ?
I have exam on following monday SO i need to get this ASAP !
THank you sooo much

 

[rukawa0929]

HELP ! Elctromagnetic Question

Ok I need to solve for Resistance, but itseems like I don't have enough info
Here's my question :

The rectangular wire loop has dimensions of 4.0cm by 3.0cm. Moving at constant
speed, the loop completely exits the 0.14T uniform magnetic field in 0.12 seconds.
The wire has a radius of 0.40mm and a resistivity of 2.15 x 10^-8 Ohm x m .

Determine:

A) the resistance of the wire

Can you please help me with this ?
I have exam on following monday SO i need to get this ASAP !
THank you sooo much

 

[pam]

R=rho L/A. You know rho, L, and A.

 

[Mindscrape]

You can figure it out using the rules for magnetic flux and emf.

$$\Phi = \iint \mathbf{B} \cdot d\mathbf{a}$$

which if the magnetic field is constant, then

$$\Phi = B*Area$$

then the emf would be

$$\epsilon = \frac{d \phi}{dt}$$

you can find the current with current density formulas and whatnot. Do some work, and we'll see how we can help you.

 

[mheslep]

Do you perhaps mean you need the impedance of the wire? Otherwise for resistance most of the given information about the shape of the wire (loop) is superfluous as Pam suggests. Only rho, L, A determine the resistance, the other information has no effect.