Questions from Modern Physics

Q: A current was sent through a helical coil spring. The spring

A current was sent through a helical coil spring. The spring contracted, as though it had been compressed. Why?

Q: A square conducting loop is in a region of uniform, constant

A square conducting loop is in a region of uniform, constant magnetic field. Can the loop be rotated about an axis along one side and no emf be induced in the loop? Discuss, in terms of the orientatio...

Q: A metal ring is oriented with the plane of its area perpendicular

A metal ring is oriented with the plane of its area perpendicular to a spatially uniform magnetic field that increases at a steady rate. If the radius of the ring is doubled, by what factor do (a). th...

Q: Small one-cylinder gasoline engines sometimes use a device called a

Small one-cylinder gasoline engines sometimes use a device called a magneto to supply current to the spark plug. A permanent magnet is attached to the flywheel, and a stationary coil is mounted adjace...

Q: Does Lenz’s law say that the induced current in a metal loop

Does Lenz’s law say that the induced current in a metal loop always flows to oppose the magnetic flux through that loop? Explain.

Q: Does Faraday’s law say that a large magnetic flux induces a large

Does Faraday’s law say that a large magnetic flux induces a large emf in a coil? Explain.

Q: Can one have a displacement current as well as a conduction current

Can one have a displacement current as well as a conduction current within a conductor? Explain.

Q: In an R-C circuit, a resistor, an uncharged

In an R-C circuit, a resistor, an uncharged capacitor, a dc battery, and an open switch are in series. In an R-L circuit, a resistor, an inductor, a dc battery, and an open switch are in series. Compa...

Q: Match the mathematical statements of Maxwell’s equations as given in Section 29

Match the mathematical statements of Maxwell’s equations as given in Section 29.7 to these verbal statements. (a). Closed electric field lines are evidently produced only by changing magnetic flux....

Q: In a two-cell flashlight, the batteries are usually connected

In a two-cell flashlight, the batteries are usually connected in series. Why not connect them in parallel? What possible advantage could there be in connecting several identical batteries in parallel?...