Posted by **Anonymous** on Saturday, March 15, 2008 at 6:12pm.

An 8m long copper wire with a cross-sectional area of 1.0 x 10^-4 m^2, in the sshape of square loop, is connected to a .10-V battery. If the loop is placed in a uniform magnetic field of magnitude .4T, what is the maximum torque that can act on it? The resistivity of copper is 1.7x10^-8 omega*m (answer: 120 N*m) I can't seem to get the answer. Any help is appreciated!

work:

I=V/R=(.10V)/((1.7x10^-8)/8m))

torque=BIA=(.4T)(I)(10^-4 m^2)

- physics -
**drwls**, Sunday, March 16, 2008 at 6:38am
You have not used the wire resistance R in the Ohm's law equation; you used resistivity, which must be multiplied bu L/A*, where A* is the cross sectional area of the wire (1.0 x 10^-4 m^2) and L is its total length (8 m). The area A that should go into your second equation is the coil area, (L/4)^2 = 4 m^2, since is it s square.

## Answer This Question

## Related Questions

- Physics - A copper wire is 7.00 m long and has a cross-sectional area of 1.00 10...
- physics - A square loop of wire of side 2.8 cm carries 3.0 A of current. A ...
- Physics - A square loop of wire of side 3.0 cm carries 3.0 A of current. A ...
- physics - A loop of surface area s1=10cm^2 placed ina uniform magnetic field Bof...
- physics - A circular wire loop has radius R = 0.327 m and carries current i = 0...
- PHYSICS - A circular loop of flexible iron wire has an initial circumference of ...
- PHYSICS - A flat loop of wire consisting of a single turn of cross-sectional ...
- physics - A flat loop of wire consisting of a single turn of cross-sectional ...
- physics - a rectangular loop with a=6.0 cm, and b=4.0 cm, moving with a velocity...
- Physics - Would someone check this please? A circular loop of wire of radius 0....

More Related Questions