Resistivity and Conductivity 0.0 / 5 ? PhysicsD.C. ElectricityASOCR Created by: louderthanbombzzCreated on: 16-03-17 21:28 If temperature is constant, this means that the conductor is ohmic, so resistance... Is constant. 1 of 14 Why does resistance change as the current increases in non-ohmic conductors? Temperature rises, so Joule heating occurs where energy is dissipated, causing resistance to rise as wire heats. 2 of 14 What is the correct power equation? P=I^2R 3 of 14 What happens when a filament lamp becomes white hot? It no longer obeys Ohms Law due to temperature increasing resistance. 4 of 14 Why is Joule heating difficult for precise resistances? The resistance increases faster with increasing temperature and current. 5 of 14 What do alloys contain, where the change in resistance is very small? Constantan. 6 of 14 What are platinum alloys used for due to their range of resistances being known? Temperature sensors. 7 of 14 What makes up a variable resistor? A battery and rheostat 8 of 14 What sorts of properties are resistance and conductance? (HINT: they are determined by length and cross-sectional area) Extensive 9 of 14 When length is doubled, what else is doubled? Resistance 10 of 14 When cross-sectional area is doubled, what else is doubled? Conductance 11 of 14 What is the formula for resistance? R=pho*L/A 12 of 14 What is the formula for conductance? G= sigma*A/L 13 of 14 What are correct units for resistivity and conductivity? Sm^-1, and ohm m 14 of 14
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