Summary

• Electric Current
• Ohm's law

• Class Quiz    Timer
  
  
  
• Resistivity
  
  Example #1
  
  
• Electric power
  • calculations and applet
    Example #2
    
    Example #3
    
  • high voltage power lines
  • cost of electricity
    Example #4
    
  
  
• alternating current

gc6 18.8
A 9.0-V battery is connected to a bulb whose resistance is 1.6 Ω. How many electrons leave the battery per second?
A. 5.62 e/s                    B. 337 e/s
C. 9.00×10¹⁹ e/s           D. 3.51×10¹⁹ e/s
Answer







sj6 27.16
A 2.0 m long, 0.012 m radius wire carries 3.00 A of current driven by V=240 V. What is the resistivity of the conductor?
A. 80.0 W·m           B. 3.54×10⁵ W·m
C. 0.112 W·m           D. 0.0181 W·m
Answer







kw4
How much current will a 50-W light bulb draw from a 12-V battery?
A. 0.24 A           B. 4.17 A
C. 12 A              D. 600 A
Answer







kw4
What power does a TV require if it draws 150 mA from the 120-V outlet?
A. 0.80 W           B. 1.25 W
C. 18 W              D. 18 kW
Answer







kw4
At a cost of 8�/kWh, what does it cost to leave a 100-W security light on during a 10 hour night?
A. $8.00             B. 80�
C. 8�                  D. 0.8�
Answer







 



D. 3.51×10¹⁹ e/s













 



D. 0.0181 W·m













 



B. 4.17 A













 



C. 18 W













 



C. 8�