# Physics Quiz 5

 A device that produces electricity by transforming chemical energy into electrical energy is called a battery A car battery has an emf of 12 V consisting of six 2-V cells connected in series. The total amount of charge that passes through a wire's full cross section at any point per unit of time is referred to as current The direction of convention current is taken to be the direction that positive charges would flow. A coulomb per second is the same as an ampere. Car batteries are rated in "amp-hours." This is a measure of their charge The resistance of a wire is defined as voltage/current What is 1 Ohm equivalent to? 1 V/A The resistance of a wire is proportional to its length and inversely proportional to its cross-sectional area The resistivity of a wire depends on the material out of which it is composed. Which conducting material has the lowest resistivity value? silver Consider two copper wires. One has twice the length of the other. How do the resistivities of these two wires compare? Both wires have the same resistivity. Consider two copper wires. One has twice the length of the other. How do the resistances of these two wires compare? The longer wire has twice the resistance of the shorter wire. Consider two copper wires. One has twice the cross-sectional area of the other. How do the resistances of these two wires compare? The thicker wire has half the resistance of the shorter wire. Consider two copper wires. One has twice the length and twice the cross-sectional area of the other. How do the resistances of these two wires compare? Both wires have the same resistance. The length of a wire is doubled and the radius is doubled. By what factor does the resistance change? half as large How much more resistance does a 1.0 cm diameter rod have compared to a 2.0 cm diameter rod of the same length and made of the same material? 300% The resistivity of most common metals increases as the temperature increases. Negative temperature coefficients of resistivity exist in semiconductors What is 1 W equivalent to? 1 V*A A kilowatt-hour is equivalent to 3,600,000 J If the resistance in a constant voltage circuit is doubled, the power dissipated by that circuit will decrease to one-half its original value. If the voltage across a circuit of constant resistance is doubled, the power dissipated by that circuit will quadruple If the resistance in a circuit with constant current flowing is doubled, the power dissipated by that circuit will double If the current flowing through a circuit of a constant resistance is doubled, the power dissipated by that circuit will quadruple Authoriishvo ID228108 Card SetPhysics Quiz 5 DescriptionPHysics Updated2013-07-25T04:08:52Z Show Answers