Questions from College Physics

Q: Suppose XL > XC in Figure 21.12. If switch

Suppose XL > XC in Figure 21.12. If switch A is left open and switch B is closed, what happens to the phase angle? (a) It increases. (b) It decreases. (c) It doesn’t change. Figu...

Q: Suppose XL > XC in Figure 21.12 and, with

Suppose XL > XC in Figure 21.12 and, with both switches open, a piece of iron is slipped into the inductor. During this process, what happens to the brightness of the bulb? (a) It increases. (b) It...

Q: Figure 20.6 is a graph of the magnitude B versus

Figure 20.6 is a graph of the magnitude B versus time for a magnetic field that passes through a fixed loop and is oriented perpendicular to the plane of the loop. Rank the magnitudes of the emf gener...

Q: A bar magnet is falling toward the center of a loop of

A bar magnet is falling toward the center of a loop of wire, with the north-pole oriented downward. Viewed from the same side of the loop as the magnet, as the north-pole approaches the loop, what is...

Q: Two circular loops are side by side and lie in the xy

Two circular loops are side by side and lie in the xy - plane. A switch is closed, starting a counterclockwise current in the left-hand loop, as viewed from a point on the positive z - axis passing th...

Q: A magneto is used to cause the spark in a spark plug

A magneto is used to cause the spark in a spark plug in many lawn mowers today. A magneto consists of a permanent magnet mounted on a flywheel so that it spins past a fixed coil. Explain how this arra...

Q: A horizontal metal bar oriented east–west drops straight down in

A horizontal metal bar oriented east–west drops straight down in a location where Earth’s magnetic field is due north. As a result, an emf develops between the ends. Which end is positively charged? (...

Q: Why is the sum of the maximum voltages across each of the

Why is the sum of the maximum voltages across each of the elements in a series RLC circuit usually greater than the maximum applied voltage? Doesn’t this violate Kirchhoff’s loop rule?

Q: An inductor and a resistor are connected in series across an AC

An inductor and a resistor are connected in series across an AC generator, as shown in Figure CQ21.16. Immediately after the switch is closed, which of the following statements is true? (a) The curren...

Q: A circular loop of wire lies below a long wire carrying a

A circular loop of wire lies below a long wire carrying a current that is increasing as in Figure P20.17a. (a) What is the direction of the induced current in the loop, if any? (b) Now suppose the loo...