22.Tock.If the lengthbincreases asb(t) =b+βt(β >0), what would be the directions ofthe induced emf and induced current?A. Both clockwiseB. Both counterclockwiseC. Clockwise emf, counterclockwise currentD. Counterclockwise emf, clockwise currentR.For the next two items, consider a thin conducting rod oflengthLriding along two parallel conducting rails withconstant velocityvas shown. The rails and the rod, bothwith negligible resistance, are connected to a resistor23.EMotional UP.If the system is immersed in a uniform constant magnetic fieldBdirectedupward, what is the induced emf produced between the rod?24.EMotional INTO.If the system is immersed in a uniform constant magnetic fieldBdi-rected into the page, what is the induced current passing through the resistor?√32vBLRvBLR25.Induced E-fields.Consider an electrostatic electric fieldE1and an induced electric fieldE2. Which of the following correctly describe/s these fields?I. Both fields are derivable from electric potentials.A – 8
Second Long ExamFirst Semester, AY 2014–2015Physics 72II.E1is produced by a static charge distribution, whileE2is induced by a changing mag-netic field.III. Each field exerts a forceFi(i= 1,2)of the formFi=qEion a chargeq.A. I onlyB. III onlyC. II and III onlyD. I, II, and III26.maxiD.Consider a charging parallel plate capacitor. Its plates have areaAand separationdistanced. What is the maximum displacement current if the electric field between theplates varies according toE(t) =E0sin(ωt)?27.oh-EM-F!A short air-core cylindrical inductor coil has self-inductanceL= 400μH. Thecurrentiin this inductor increases uniformly from 0 to16 Ain4.0μs. What is the magni-tude and direction of the self-induced emf?A.1.0×10-10V, along the direction ofiB.1.0×10-10V, opposite to direction ofiC.1.6×103V, along the direction ofiD.1.6×103V, opposite to direction ofi28.induc-THOR.A flat spiral air-core inductor coil has self-inductanceL= 40μH. Thecurrentiin this inductor decreases uniformly from8.0 Ato4.0 Ain2.0μs. What is themagnitude and direction of the self-induced emf?29.LC ka?A1 mFcapacitor is charged by connecting to a10 Vdc power supply.Thecapacitor is disconnected to the power supply and then connected across an inductor. Theangular frequency of the oscillation is5×102rad/s. What is themaximumcurrent in thecircuit?