Questions from Modern Physics

Q: Nerve cells transmit electric signals through their long tubular axons. These

Nerve cells transmit electric signals through their long tubular axons. These signals propagate due to a sudden rush of Na+ ions, each with charge +e, into the axon. Measurements have revealed that ty...

Q: A ductile metal wire has resistance R. What will be the

A ductile metal wire has resistance R. What will be the resistance of this wire in terms of R if it is stretched to three times its original length, assuming that the density and resistivity of the ma...

Q: In household wiring, copper wire 2.05 mm in diameter

In household wiring, copper wire 2.05 mm in diameter is often used. Find the resistance of a 24.0-m length of this wire.

Q: A parallel-plate capacitor has the volume between its plates filled

A parallel-plate capacitor has the volume between its plates filled with plastic with dielectric constant K. The magnitude of the charge on each plate is Q. Each plate has area A, and the distance bet...

Q: What diameter must a copper wire have if its resistance is to

What diameter must a copper wire have if its resistance is to be the same as that of an equal length of aluminum wire with diameter 2.14 mm?

Q: You apply a potential difference of 4.50 V between the

You apply a potential difference of 4.50 V between the ends of a wire that is 2.50 m in length and 0.654 mm in radius. The resulting current through the wire is 17.6 A. What is the resistivity of the...

Q: A carbon resistor is to be used as a thermometer. On

A carbon resistor is to be used as a thermometer. On a winter day when the temperature is 4.0°C, the resistance of the carbon resistor is 217.3 Ω. What is the temperature on a spring day when the resi...

Q: When a resistor with resistance R is connected to a 1.

When a resistor with resistance R is connected to a 1.50-V flashlight battery, the resistor consumes 0.0625 W of electrical power. (Throughout, assume that each battery has negligible internal resista...

Q: A battery-powered global positioning system (GPS) receiver operating

A battery-powered global positioning system (GPS) receiver operating on 9.0 V draws a current of 0.13 A. How much electrical energy does it consume during 30 minutes?

Q: Ordinary household electric lines in North America usually operate at 120 V

Ordinary household electric lines in North America usually operate at 120 V. Why is this a desirable voltage, rather than a value considerably larger or smaller? On the other hand, automobiles usually...