Chapter 18
1. (p.551 prob.8) A hair dryer draws 9.0A when plugged into a 120-V line. (a) What is its resistance? (b) How much charge passes through it in 15min?
2. (p.551 prob.17) A length of aluminum wire is connected to a precision 10.00-V power supply, and a current of 0.4212A is precisely measured at 20.0°C. The wire is placed in a new environment of unknown temperature where the measured current is 0.3618A. what is the unknown temperature?
3. (p.552 prob.33) A transistor to be used in a circuit is rated for a maximum current of 25mA if operated at 9.0V. (a) What is the maximum power output of the transistor, aand (b) what would be the limiting current if the voltage applied where actually only 7.0V?
4. (p.553 prob.44) Calculate the peak voltage and peak current through an 1800-W arc welder connected to a 450-V ac line.