PHY 102 WEEK 8 90% GUARANTEED EXAM QUESTIONS AND CORRECT ANSWERS.

PHY 102 WEEK 8 90% GUARANTEED EXAM QUESTIONS AND CORRECT ANSWERS. The flow of charge in a circuit depends on adequate resistance. a potential difference. adequate chemical action. all of the above - Answers a potential difference. The purpose of a voltage source is to provide an electrical energy sink. pressure. field - Answers pressure. When we talk about electric power we're talking joules per second. watts. both neither - Answers both A water molecule is electrically polarized. insulating. conducting. charged. - Answers polarized The current in a 10-ohm resistor is 5 A. What is the voltage across the resistor? 20 V 15 V more than 20 V 10 V 5 V - Answers more than 20 V A sustained flow of electric charge requires a potential difference. a resistance. an electric field. electric polarization. - Answers a potential difference. What is the effect on current through a circuit of steady resistance when the voltage is doubled? current is halved current is doubled current doesn't change - Answers current is doubled When both voltage and resistance are doubled? current is halved current is doubled current doesn't change - Answers current doesn't change If you double both the current and the voltage in a circuit, the power _______. quadruples remains unchanged if resistance remains constant halves doubles - Answers quadruples What is the resistance of a 120-W incandescent lamp connected to a 120-V power supply? 144 ohms 1 ohm 100 ohms 60 ohms none of the above - Answers none of the above The electric current in a copper wire is normally composed of _______. electrons protons ions electrons, protons, and/or ions - Answers electrons To say a circuit is dc is to say that current in the circuit is parallel to the connecting wires. has a single direction. alternates only slowly. - Answers has a single direction. As more lamps are put into a parallel circuit, the overall current in the power source remains the same. decreases. increases - Answers increases Coulomb's law is similar in form to _______. Newton's law of gravity all of Newton's laws of motion Ohm's law Faraday's law - Answers Newton's law of gravity Two lamps, one with a thick filament and one with a thin filament, are connected in parallel. The current is greater in the lamp with the thick filament. thin filament. same in each - Answers thick filament. A compact fluorescent lamp gives more light output for less power. the same power. greater resistance. - Answers less power. If 6 V were impressed across the circuit, consisting of two lamps connected in series, and the voltage across the first lamp were 2 V, what would be the voltage across the second lamp? - Answers 4 V When a steady voltage is across one-half as much resistance, the current remains the same. is quadrupled. is half. is doubled. - Answers is doubled. The unit of resistance is named after Georg Simon Ohm. Micheal Faraday. Isaac Newton. Benjamin Franklin. Charles Coulomb - Answers Georg Simon Ohm. A negatively charged rod is brought near a metal can that rests on a wood table. You touch the opposite side of the can momentarily with your finger. The can then becomes negatively charged. uncharged. positively charged. - Answers positively charged. Electric potential is measured in units of volts. watts. amperes. joules. any or all of these - Answers volts. When we say an appliance "uses up" electricity, we actually are saying that