A wire 4.00 m long and 6.00 mm in diameter has a resistance of 15.0 m$\Omega$. A potential difference of 23.0 V is applied between the ends. Calculate the resistivity of the wire material.

A wire $4.00 \mathrm{~m}$ long and $6.00 \mathrm{~mm}$ in diameter has a resistance of $12.0 \mathrm{~m} \Omega$. A potential difference of $45.0 \mathrm{~V}$ is applied between the ends. Calculate the resistivity of the wire material.

A wire $4.00 \mathrm{~m}$ long and $6.00 \mathrm{~mm}$ in diameter has a resistance of $12.0 \mathrm{~m} \Omega$. A potential difference of $45.0 \mathrm{~V}$ is applied between the ends. What is the current in the wire?

The electrical resistance of a copper wire varies directly with its length and inversely with the square of the diameter of the wire. If a wire $30 \mathrm{~m}$ long with a diameter of $3 \mathrm{~mm}$ has a resistance of $25\ \Omega$, determine the resistance of a wire $40 \mathrm{~m}$ long with a diameter of $3.5 \mathrm{~mm}$.

The given figure shows three plastic sheets that are large, parallel, and uniformly charged. Another figure gives the component of the net electric field along an $x$ axis through the sheets. What is the ratio of the charge density on sheet 3 to that on sheet 2 ?

A certain cylindrical wire carries current. We draw a circle of radius r around its central axis in Figure to determine the current i within the circle. The figure shows current i as a function of $r^2$. Is the current density uniform?

A certain cylindrical wire carries current. We draw a circle of radius $r$ around its central axis in the above Fig. to determine the current $i$ within the circle. The above Figure shows current $i$ as a function of $r^2$. The vertical scale is set by $i_s=8.0 \mathrm{~mA}$, and the horizontal scale is set by $r_s^2=4.0 \mathrm{~mm}^2$. If so, what is its magnitude?

Given the waveform of a voltage source shown in the given figure, find: a. The steady DC voltage that would cause the same heating effect across a resistance. b. The average current supplied to a $10-\Omega$ resistor connected across the voltage source. c. The average power supplied to a $1-\Omega$ resistor connected across the voltage source.

The voltage source shown in figure is measured to have an open-circuit voltage of $24 \mathrm{~V}$. When a $10-\Omega$ load is connected across the terminals, the voltage measured with a voltmeter drops to $22.8 \mathrm{~V}$. a. Determine the internal resistance of the voltage source. b. If the source had only half the resistance determined in (a), what voltage would be measured across the terminals with the $10-\Omega$ resistor connected?

Given the waveform of a voltage source shown in Figure, find: a. The steady DC voltage that would cause the same heating effect across a resistance. b. The average current supplied to a $10-\Omega$ resistor connected across the voltage source. c. The average power supplied to a $1-\Omega$ resistor connected across the voltage source.

The equilibrium fraction of lattice sites that are vacant in silver $(\mathrm{Ag})$ at $700^{\circ} \mathrm{C}$ is $2 \times 10^{-6}$. Calculate the number of vacancies (per meter cubed) at $700^{\circ} \mathrm{C}$. Assume a density of $10.35 \mathrm{~g} / \mathrm{cm}^3$ for $\mathrm{Ag}$.

What is the resistance of a wire with radius 0.500 mm and length 4.3 m, made from a material with resistivity

$$2.0 \times 10 ^ { - 8 } \Omega \cdot m$$

?

A $32-\mu \mathrm{F}$ capacitor is connected across a programmed power supply. During the interval from $t=0$ to $t=3 \mathrm{~s}$, the output voltage of the supply is given by $V(t)=(6 \mathrm{~V})+(4 \mathrm{~V} / \mathrm{s}) t$ $\left(2 \mathrm{~V} / \mathrm{s}^2\right) t^2$. At $t=0.50 \mathrm{~s}$, find $(a)$ the charge on the capacitor. (b) the current into the capacitor, and (c) the power output from the power supply.

Iron and vanadium both have the BCC crystal structure, and V forms a substitutional solid solution for concentrations up to approximately 20 wt% at room temperature. Compute the unit cell edge length for a 90 wt% Fe-10 wt% V alloy.