Questions from Modern Physics

Q: If you walk across a nylon rug and then touch a large

If you walk across a nylon rug and then touch a large metal object such as a doorknob, you may get a spark and a shock. Why does this tend to happen more on dry days than on humid days? (Hint: See Fig...

Q: You have a negatively charged object. How can you use it

You have a negatively charged object. How can you use it to place a net negative charge on an insulated metal sphere? To place a net positive charge on the sphere?

Q: The potential difference between the two terminals of an AA battery (

The potential difference between the two terminals of an AA battery (used in flashlights and portable stereos) is 1.5 V. If two AA batteries are placed end to end with the positive terminal of one bat...

Q: If the electric potential at a single point is known, can

If the electric potential at a single point is known, can

Q: A point charge of mass m and charge Q and another point

A point charge of mass m and charge Q and another point charge of mass m but charge 2Q are released on a frictionless table. If the charge Q has an initial acceleration a0, what will be the accelerati...

Q: Because electric field lines and equipotential surfaces are always perpendicular, two

Because electric field lines and equipotential surfaces are always perpendicular, two equipotential surfaces can never cross; if they did, the direction of

Q: In Example 21.1 (Section 21.3) we

In Example 21.1 (Section 21.3) we saw that the electric force between two

Q: In electronics it is customary to define the potential of ground (

In electronics it is customary to define the potential of ground (thinking of the earth as a large conductor) as zero. Is this consistent with the fact that the earth has a net electric charge that is...

Q: Two irregular objects A and B carry charges of opposite sign.

Two irregular objects A and B carry charges of opposite sign. Figure Q21.19 shows the electric field lines near each of these objects. Figure Q21.19: (a). Which object is positive, A or B? How do...

Q: Atomic nuclei are made of protons and neutrons. This shows that

Atomic nuclei are made of protons and neutrons. This shows that there must be another kind of interaction in addition to gravitational and electric forces. Explain.