1.1 × 1020 electrons flow through a cross section of a 2.4-mm-diameter iron wire in 6.0 s. Part A What is the electron drift speed? Express your answer in micrometers per second. ▸ View Available Hint(s) V ΕΠΙ ΑΣΦ V-7.90 Submit Previous Answers × Incorrect; Try Again ? μm/s

What does the term fibrillation mean in connection with heart function? Give two important causes of heart fibrillation in human beings. How do pacemakers and defibrillators help to prolong life for patients suffering from this condition?

A 10.00-meter long wire cable that is made of copper has a resistance of 0.051 ohms, (a) What is the weight if the wire was made of copper? (b) What is the weight of a 10.00-meter-long wire of the same gauge made of aluminum? (c)What is the resistance of the aluminum wire? The density of copper is 8960 kg/m3 and the density of aluminum is 2760 kg/m3.

Unreasonable Results (a) What current is needed to transmit 1.00 102 MW of power at 10.0kV? (b) Find the resistance of 1.00 km of wire that would cause a 0.0100% power loss. (c) What is the diameter of a 1.00-km-long copper wire having this resistance? (d) What is unreasonable about these results? (e) Which assumptions are unreasonable, or which premises are inconsistent?

A 20.00-V battery is used to supply current to a 10-k resistor. Assume the voltage drop across any wires used for connections is negligible, (a) What is the current through the resistor? (b) What is the power dissipated by the resistor? (c) What is the power input from the battery; assuming all the electrical power is dissipated by the resistor? (d) What happens to the energy dissipated by the resistor?

(a) During surgery, a current as small as 20.0A applied directly to the heart may cause ventricular fibrillation. If the resistance of the exposed heart is 300 what is the smallest voltage that poses thisdanger? (b) Does your answer imply that special electrical safetyprecautions are needed?

a) Of what material is a wire made, if it is 25.0 m long with a 0.100 mm diameter and has a resistance of 77.7at 20,0°C ? (b) What is its resistance at 150°C ?

The quantity of charge through a conductor is modeledas Q=4.00Cs4t41.00Cst+6.00mc .What is the current at time t = 3.00 s?

A close analogy exists between the flow of energy by heat because of a temperature difference (see Section 19.6) and the flow of electric charge because of a potential difference. In a metal, energy dQ and electrical charge dq are both transported by free electrons. Consequently, a good electrical conductor is usually a good thermal conductor as well. Consider a thin conducting slab of thickness dx, area A, and electrical conductivity , with a potential difference dV between opposite faces. (a) Show that the current I = dq/dt is given by the equation on the left: ChargeconductionThermalconductiondqdt=A|dVdx|dQdt=kA|dTdx| In the analogous thermal conduction equation on the right (Eq. 19.17), the rate dQ/dt of energy flow by heat (in SI units of joules per second) is due to a temperature gradient dT/dx in a material of thermal conductivity k. (b) State analogous rules relating the direction of the electric current to the change in potential and relating the direction of energy flow to the change in temperature.

The current I is measured through a sample of an ohmic material as a voltage V is applied, (a) What is the current when the voltage is doubled to 2V (assume the change in temperature of the material is negligible)? (b) What is the voltage applied is the current measured is 0.27 (assume the change in temperature of the material is negligible)? What will happen to the current if the material if the voltage remains constant, but the temperature of the material increases significantly?