PHY 2049: Physics IIHITT 1CurrentsResistancesSuperconductorsCircuits, JunctionsResistances n circuitWork and emfSlide 9More Resistance in parallelHITT2PHY 2049: Physics IITutoring Center is open in room NPB 1215, M-F 12:00AM -4:00PM. It is free.HITT 1You buy a “75W” light bulb. The label means that:A. no matter how you use the bulb, the power will be 75WB. the bulb was filled with 75W at the factoryC. the actual power dissipated will be much higher than 75W since most of the power appears as heatD. the bulb is expected to burn out after you use up its 75WE. none of the aboveCurrents Sample problem 26-2.A. 1.9 AB. 7.1 AResistancesR = ρl/ARank them by current, lowest first.SuperconductorsResistance is zero –transmission losses, switchesMagnetic field is expelled -levitationSmall thermal conductivity - thermal switchesSQUID - low fields and low voltagesCircuits, JunctionsCharge can not be created, nor destroyedTotal Current in = Total current outi = 8A -Resistances n circuitin series R = R1 + R2In parallel 1/R = 1/R1 + 1/R2Work and emfPumping of chargesPotential difference around a loop adds to zeroResistancesEach of the resistors in the diagram has a resistance of 12 Ω. The resistance of the entire circuit isMore Resistance in parallelA coaxial cable consists of a wire of material A, resistivity ρA radius R1, surrounded by a shell of another material B with resistivity ρB . The total radius is R2. What is its resistance (per unit length)?1212221111RRRlRBAHITT2A total resistance of 3.0 Ω is to be produced by combining an unknown resistor R with a 12 Ω resistor. What is the value of R and how is it to be connected to the 12 Ω resistor?A. 4.0 Ω, parallelB. 4.0 Ω, seriesC. 2.4 Ω, parallelD. 2.4 Ω, seriesE. 9.0 Ω,
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