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Electrical Power and Energy 1. An electrical appliance draws 9.0 amperes of current when connected to a 120-volt source of potential difference. What is the total amount of power dissipated by this appliance? (1) 13 W (3) 130 W (2) 110 W (4) 1100 W 6. The heating element on an electric stove dissipates 4.0 × 102 watts of power when connected to a 120-volt source. What is the electrical resistance of this heating element? (1) 0.028 Ω (3) 3.3 Ω (2) 0.60 Ω (4) 36 Ω 2. In a series circuit containing two lamps, the battery supplies a potential difference of 1.5 volts. If the current in the circuit is 0.10 ampere, at what rate does the circuit use energy? (1) 0.015 W (3) 1.5 W (2) 0.15 W (4) 15 W 7. As the resistance of a constant-voltage circuit is increased, the power developed in the circuit (1) decreases (3) remains the same (2) increases 3. One watt is equivalent to one (1) N•m (3) J•s (2) N/m (4) J/s 8. A 4.50-volt personal stereo uses 1950 joules of electrical energy in one hour. What is the electrical resistance of the personal stereo? (1) 433 Ohms (3) 37.4 Ohms (2) 96.3 Ohms (4) 0.623 Ohms 4. As the potential difference across a given resistor is increased, the power expended in moving charge through the resistor (1) decreases (3) remains the same (2) increases 9. If 60. joules of work are required to move 5.0 coulombs of charge between two points in an electric field, what is the potential difference between these points? (1) 5.0 V (3) 60. V (2) 12 V (4) 300 V 5. While operating at 120 volts, an electric toaster has a resistance of 15 ohms. The power used by the toaster is (1) 8.0 W (3) 960 W (2) 120 W (4) 1,800 W 10. A device operating at a potential difference of 1.5 volts draws a current of 0.20 ampere. How much energy is used by the device in 60. seconds? (1) 4.5 J (3) 12 J (2) 8.0 J (4) 18 J 11. How much electrical energy is required to move a 4.00microcoulomb charge through a potential difference of 36.0 volts? (3) 1.44 × 10–4 J (1) 9.00 × 106 J (2) 144 J (4) 1.11 × 10–7 J Electrical Power and Energy Answer Key [New Exam] 1. 4 2. 2 3. 4 4. 2 5. 3 6. 4 7. 1 8. 3 9. 2 10. 4 11. 3