Assignment:
Question 1. The filament of a light bulb has a resistance of 580 ?. A voltage of 120 V is connected across the filament. How much current is in the filament?
Question 2. A cylindrical copper cable carries a current of 1200 A. There is a potential difference of 1.6 X 10-2 V between two points of the cable that are 0.24 m apart. What is the radius of the cable?
Question 3. A blow-dryer and a vacuum cleaner each operate with a voltage of 120 V. The current rating of the blow-dryer is 11 A, and that of the vacuum cleaner is 4.0 A. Determine the power consumed by (a) the blow-dryer and (b) the vacuum cleaner. (c) Determine the ratio of the energy used by the blow-dryer in 15 minutes to the energy used by the vacuum cleaner in one-half hour.
Question 4. An electric furnace runs nine hours a day to heat a house during January (31 days). The heating element has a resistance of 5.3 ? and carries a current of 25 A. The cost of electricity is $0.10/kWh. Find the cost of running the furnace for the month of January.
Question 5. A 36.0-? resistor and an 18.0-? resistor are connected in series across a 15.0-V battery. What is the voltage across (a) the 36.0-? resistor and (b) the 18.0-? resistor?
Question 6. A new “D” battery has an emf of 1.5 V. When a wire of negligible resistance is connected between the terminals of the battery, a current of 28 A is produced. Find the internal resistance of the battery.
Question 7. Two batteries, each with an internal resistance of 0.015 ?, are connected as in the drawing. In effect, the 9.0-V battery is being used to charge the 8.0-V battery. What is the current in the circuit?
Question 8. A galvanometer with a coil resistance of 12.0 ? and a full-scale current of 0.15 mA is used with a shunt resistor to make an ammeter. The ammeter registers a maximum current of 4.00 mA. Find the equivalent resistance of the ammeter.
Question 9. Determine the equivalent capacitance between A and B for the group of capacitors in the drawing.
Question 10. The circuit in the drawing contains two resistors and two capacitors that are connected to a battery via a switch. When the switch is closed, the capacitors begin to charge up. What is the time constant for the charging process?
