physics HW #4 - Physics 112 HW#4 1 A cigarette lighter in a car is a resistor that when activated is connected across the 12-V battery Suppose that a

# physics HW #4 - Physics 112 HW#4 1 A cigarette lighter in a...

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Physics 112 HW #4 April 23, 2010 1. A cigarette lighter in a car is a resistor that, when activated, is connected across the 12-V battery. Suppose that a lighter uses 25.3 W of power. (a) Find the resistance of the lighter. (b) Find the current that the battery delivers to the lighter. 2. A blow-dryer and a vacuum cleaner each operate with a voltage of 120 V. The current rating of the blow-dryer is 12 A, and that of the vacuum cleaner is 4.0 (a) Determine the power consumed by the blow-dryer. A. (b) Determine the power consumed by the vacuum cleaner. (c) Determine the ratio of the energy used by the blow-dryer in 13 minutes to the energy used by the vacuum cleaner in one-half hour. 3. A 55.0-W lamp is placed in series with a resistor and a 120.0-V source. If the voltage across the lamp is 24 V, what is the resistance Rof the resistor?
Physics 112 HW #4 April 23, 2010