|Chapter 22 Exercises: 6, 10, 19, 36, 39, 54
6. When you remove your wool suit from the dry cleaner's garment bag, the bag becomes positively charged. Explain how this occurs.
10. Why are the tires for trucks carrying gasoline and other flammable fluids manufactured to be electrically conducting?
19. When one material is rubbed against another, electrons jump readily from one to the other but protons do not. Why is this? (Think in atomic terms.)
36. If you are caught outdoors in a thunderstorm, why should you not stand under a tree? Can you think of a reason why you should not stand with your legs far apart? Or why lying down can be dangerous? (Hint: Consider electric potential difference.)
39. When a car is moved into a painting chamber, a mist of paint is sprayed around its body. When the body is given a sudden electric charge and mist is attracted to it - presto - the car is quickly and uniformly painted. What does the phenomenon of polarization have to do with this? Explain.
54. Why is it safe to remain inside a car during a lightning storm? Defend your answer.
|Chapter 23 Exercises: 1, 9, 12, 15, 20, 28, 46
1. What two things can be done to increase the amount of flow in a water pipe? Similarly, what two things can be done to increase the current in an electrocal circuit?
9. In which of the circuits below does a current exist to light the bulb?
|12. Suppose you leave your car lights on while at a movie. When you return, your battery is too “weak” to start your car. A friend comes and gives you a jump start with his battery and battery cables. What physics occurs when your friend gives you a jump start?
15. Why is the current in an incandescent bulb greater immediately after it is turned on, than a few moments later?
20. Why does the filament of a lightbulb glow while the connecting wires do not? Explain.
28. A car's headlights dissipate 40 W on low beam, and 50 W on high beam. Is there more or less resistance in the high-beam filament?
46. In the circuit shown, how do the brightnesses of the identical lightbulbs compare? Which lightbulb draws the most current? What will happen if bulb A is unscrewed? If C is unscrewed?