Physics - Chapter 19 Study
Guide
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1. What are the power ratings on light bulbs a measure
of?
2. When you flip a switch to turn on a light, what determines the delay time before a light turns on?
3. What effect does length and temperature have on the resistance of a wire?
4. How is current affected if the time interval decreases while the amount of charge remains the same?
5. Draw a graph that would illustrate alternating current and direct current.
6. By what factor would the power be changed in a circuit if the current is quadrupled?
7. What happens to the resistance of a superconductor when its temperature drops below the critical temperature?
8. What happens when electrons move through a metal conductor?
9. What effect would doubling the current and making the resistance half as big have on the power dissipated by a resistor?
10. What happens to the motion of the charges in an alternating current?
11. The amount of charge that moves through the filament of a microwave in 10.0 s is 24.2 C. What is the current in the microwave?
12. A microwave draws 5.0 A when it is connected to a 120 V outlet. If electrical energy costs $0.090 per kW·h, what is the cost of running the microwave for exactly 6 h?
13. A lamp is connected across a 120 V outlet. If the resistance of the lamp is 240 S, how much power is dissipated in the form of electromagnetic radiation, heat, and light?
14. If a 325 W heater has a current of 6.0 A, what is the potential difference across the ends of the heating element?
15. How much current is in a resistor of 280 S
if there is a potential difference of 120 V across the resistor?
16. If a 75 W light bulb operates at a voltage of 120 V, what is the resistance
of the light bulb?
17. A wire carries a steady current of 0.1 A over a period of 20 s. What total charge moves through the wire in this time interval?
18. A potential difference of 4.0 V is placed across a resistor with 10.0 A of current in it. What is the resistance of the resistor?