Questions from Modern Physics

Q: The electric force between two charged particles becomes weaker with increasing distance

The electric force between two charged particles becomes weaker with increasing distance. Suppose instead that the electric force were independent of distance. In this case, would a charged comb still...

Q: A student asked, “Since electrical potential is always proportional to

A student asked, “Since electrical potential is always proportional to potential energy, why bother with the concept of potential at all?” How would you respond?

Q: A certain region of space bounded by an imaginary closed surface contains

A certain region of space bounded by an imaginary closed surface contains no charge. Is the electric field always zero everywhere on the surface? If not, under what circumstances is it zero on the sur...

Q: In Fig. 22.15, suppose a third point charge

In Fig. 22.15, suppose a third point charge were placed outside the purple Gaussian surface C. Would this affect the electric flux through any of the surfaces A, B, C, or D in the figure? Why or why n...

Q: You find a sealed box on your doorstep. You suspect that

You find a sealed box on your doorstep. You suspect that the box contains several charged metal spheres packed in insulating material. How can you determine the total net charge inside the box without...

Q: Since potential can have any value you want depending on the choice

Since potential can have any value you want depending on the choice of the reference level of zero potential, how does a voltmeter know what to read when you connect it between two points?

Q: Good conductors of electricity, such as metals, are typically good

Good conductors of electricity, such as metals, are typically good conductors of heat; insulators, such as wood, are typically poor conductors of heat. Explain why there is a relationship between cond...

Q: In a conductor, one or more electrons from each atom are

In a conductor, one or more electrons from each atom are free to roam throughout the volume of the conductor. Does this contradict the statement that any excess charge on a solid conductor must reside...

Q: If E ⃗ is zero throughout a certain region of space, is the

  If E ⃗ is zero throughout a certain region of space, is the potential necessarily also zero in this region? Why or why not? If not, what can be said about the potential?

Q: A diesel engine performs 2200 J of mechanical work and discards 4300

A diesel engine performs 2200 J of mechanical work and discards 4300 J of heat each cycle. (a). How much heat must be supplied to the engine in each cycle? (b). What is the thermal efficiency of the...