What is the resistivity of a wire of 5-gauge wire (A = 16.8 $\times$ 10$^{−6}$ m$^2$ ), 5.00 m length, and 5.10 m $\Omega$ resistance?

In figure mentioned shows two masses hanging from a steel wire. The mass of the wire is $60.0 \mathrm{~g}$. A wave pulse travels along the wire from point 1 to point 2 in $24.0 \mathrm{~ms}$. What is mass $m$ ?

A wire is used to hang a painting from a nail on a wall as shown at the right. The tension on each half of the wire is equal to half the downward force times $\sec \frac{\theta}{2}$. Write an equation that represents the tension on each half of the wire.

C. The magnetic force acting on a wire that is perpendicular to a 1.5 T uniform magnetic field is 4.4 N. If the current in the wire is 5.0 A, what is the length of the wire that is inside the magnetic field? Given: Unknown: $\ell=\frac{F_{\text {magnatic}}}{B I}=$

What fraction of the current in a wire of radius $R$ flows in the part of the wire with radius $r \leq \frac{1}{2} R$ ?

Explain how you can determine the direction of a magnetic field produced by a wire if you know the direction of current through the wire.

In many transformers, the wire around one winding is thicker, and therefore has lower resistance, than the wire around the other winding. If the thicker wire is wrapped around the secondary winding, is the device a step-up or a step-down transformer? Explain.

If you have a fixed magnetic field and a length of wire, how can you increase the induced emf across the ends of the wire?

A long, straight wire carries a current, as shown in the figure. A single electron is shot directly toward the wire from above. The trajectory of the electron and the wire are in the same plane. Will the electron be deflected from its initial path, and if so, in which direction?

A 2.50-m-long copper wire has $1.50 \mathrm{~V}$ across its ends. (a) Find the electric field strength within the wire.

If an electric wire is allowed to produce a magnetic field no larger than that of the Earth $\left(0.50 \times 10^{-4} \mathrm{~T}\right)$ at a distance of $12 \mathrm{~cm}$ from the wire, what is the maximum current the wire can carry?

A landscaper attaches a guy wire 10 ft up the trunk of a newly planted sapling. He stakes the wire between 20 and 25 feet from the tree. What could be the length of the guy wire if it forms a right triangle with the tree?

A wire is used to hang a painting from a nail on a wall as shown at the right. The tension on each half of the wire is equal to half the downward force times $\sec \frac{\theta}{2}$. What is the least amount of tension on each side of the wire?

A battery is connected to a Nichrome wire and a conventional current of 0.3 A runs through the wire. The wire is laid out in the form of a rectangle 50 cm by 3 cm. (a) What is the approximate magnetic field at the center of the rectangle? Give the direction as well as the magnitude.