Reading Quiz #17 1) EMF stands for … Electromagnetic force Electromagnetic flux Electromotive force 2) Faraday’s Law says that the emf induced in a loop is proportional to the current enclosed in the loop proportional to the magnetic field around the loop proportional to the magnetic flux through the loop proportional to the change of the magnetic flux through the loop

Reading Quiz #18 An electric generator … a) Is the reverse of an electric motor b) Changes mechanical energy into electrical energy c) All of the above d) None of the above 2) The secondary voltage in a transformer is … a) Higher if the number of secondary turns is lower b) Higher if the number of secondary turns is higher c) Only the currents are transformed

Reading Quiz #19 The self-inductance L of a device … a) … occurs only in dc circuits b) … impedes the flow of a current through a device c) … is a property of the device d) two of the above 2) The energy stored in an inductor is proportional to a) I b) I2 c) I3 3) The unit of inductance is Weber b) Tesla c) Henry d) Farad

Reading Quiz #20 When an LR circuit is first disconnected from a battery, the current decays … a) linearly b) logarithmically c) instantaneously d) exponentially 2) In an EM oscillator, what is oscillating? Charge Q Current I Inductance L All of the above Two of the above

Reading Quiz #21 What happens at resonance in an AC circuit? In AC circuits the current and the voltage are in phase voltage is ahead of current current is ahead of voltage Depends on the specific circuit What happens at resonance in an AC circuit? Voltage is maximal Voltage is minimal Current is maximal Current is minimal

Reading Quiz #22 How many Maxwell equations are there? two b) three c) four d) five e) six Which of the following is not one of Maxwell’s equations? Ohm’s law Gauss’ law Faraday’s law Ampere’s law

Reading Quiz #23 Which of the following is not an EM wave? X rays Radio waves Microwaves Sound waves Light The higher the frequency of an EM wave… a) the lower its energy b) the shorter its wavelength c) the lower its velocity d) two of the above