# Physics

A piece of copper wire has a resistance per unit length of 5.50 x 10^-3 Ω/m. The wire is wound into a thin, flat coil of many turns that has a radius of 0.200 m. The ends of the wire are connected to a 12.0-V battery. Find the magnetic field strength at the center of the coil.

1. 👍 0
2. 👎 0
3. 👁 439
1. Magnetic ﬁeld at the center of a circular current-carrying loop of N turns and radius r is
B=Nμ₀I/2r….. (1)
N=L/2πr ….(2)
I=U/R=U/R₀L ….(3)
Substitution (2) and (3) in (1) gives
B=Nμ₀I/2r = (L/2πr) •(μ₀/2r) •(U/R₀L) = μ₀U/4πr²R₀=
=4π•10⁻⁷•12/ 4π •(0.2)² •5.5•10⁻³ =5.45•10⁻³ T

1. 👍 0
2. 👎 0

## Similar Questions

1. ### physics

Consider two copper wires with the same cross-sectional area. Wire A is twice as long as wire B. How do the resistivities and resistances of the two wires compare? CHECK ALL THAT APPLY Wire A and wire B have the same resistance.

2. ### probability

A factory produces copper wires. A blue mark is placed on a very long length of copper. The wire is then cut into pieces. The lengths of different pieces are independent, and the length of each piece is distributed according to

3. ### Math

A copper solid cylinder of radius 14cm and height 10cm is melted and recast into cylindrical wire of diameter 4mm.find the length of the copper wire

4. ### physics

A copper wire has a resistance of 0.425 at 20.0°C, and an iron wire has a resistance of 0.455 at the same temperature. At what temperature are their resistances equal?

1. ### Math

Problem: What is the resistance of a 3.9-m length of copper wire 1.1 mm in diameter? The resistivity of copper is 1.68×10^−8Ω⋅m. Answer--> R=______Ω

2. ### Physics

Two wires with the same resistance have the same diameter but different lengths. If wire 1 has length L1 and wire 2 has length L2, how do L1 and L2 compare if wire 1 is made from copper and wire 2 is made from aluminum? The

3. ### Physics

Two wires are identical, except that one is aluminum and one is copper. The aluminum wire has a resistance of 0.835. What is the resistance of the copper wire? Take the resistivity of copper to be 1.72 x 10-8 Ω·m, and that of

4. ### physics

A wire of initial length L0 and radius r0 has a measured resistance of 2.5 . The wire is drawn under tensile stress to a new uniform radius of r = 0.45r0. What is the new resistance of the wire?

1. ### Physics!! Help!!!!!

A wire of length L and cross-sectional area A has resistance R. What will be the resistance R_stretched of the wire if it is stretched to twice its original length? Assume that the density and resistivity of the material do not