Aeroflot An airplane is flying in such a way that the Earths magnetic field

Aeroflot an airplane is flying in such a way that the

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23.Aeroflot.An airplane is flying in such a way that the Earth’s magnetic field, with local fieldstrength0.30 mT, forms an angle of30relative to the direction of motion of the airplane.If the plane is cruising at a speed of150 m/s, and if the plane has a wingspan of10 m, whatis the induced EMF across the plane’s wings? A.0.003 VB.0.225 VC.0.390 VD.0.450 VSolution:vBLsinθ 24.Electrostatic vs induced.Which of the following statements is ALWAYS TRUE?I. The notion of the potential difference makes sense only for electrostatic fields.II. The work done by induced electric fields on a point charge moved along a closed pathis zero.III. The work done by electrostatic fields are path-dependent. B – 13
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Second Long ExamMidyear, AY 2015–2016Physics 72Solution:yeah 25.All by myself.A coil has a self inductance of0.5 H. If the current in coil 2 varies asI(t) = 3t2-4t(in SI units), what will be the magnitude of the induced emf in the coilafter1 s? 26.MU.Two solenoids have an unknown mutual inductance. The EMF in solenoid 1 is3.0 Vwhen the current in solenoid 2 changes by1.0 A/s. What is the EMF in solenoid 2 whenthe current in solenoid 1 changes by2.0 A/s? . B – 14
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Second Long ExamMidyear, AY 2015–2016Physics 72 27.induc-THOR.An inductor coil has self-inductanceL= 40μH.The currentiin thisinductor decreases uniformly from8.0 Ato4.0 Ain2.0μs. What is the magnitude anddirection of the self-induced emf? A.20 V, along the direction ofiB.40 V, opposite the direction ofiC.80 V, along the direction ofiD.240 V, opposite the direction ofiSolution:|E|=L|didt|, deccreasing current: direction of emf same with direction ofcurrent 28.Solenoid Heussaff.A tightly wound solenoid withNturns and lengthlcarries currentI.What is the magnetic energy density inside the solenoid?2I2N2I22μ0l2C.μ0N2I22N2I2 29.I-induct na lamang.A coil that has a self-inductance of2.00 Hand a resistance of12.0 Ωis connected to an ideal24.0-Vbattery. How much energy is stored in the inductor whenthe steady-state current is established? 12.0 Ω= 2.00 ACalculate for the energy stored in the inductor.U=12LI2=12(2.00 H)(2.00 A)
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Second Long ExamMidyear, AY 2015–2016Physics 72
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  • Spring '11
  • Departmental
  • Physics, Magnetic Field

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