PHYS-115(x) (Kaldon-xxxxx) Name ______________________________________________WMU - Winter 2001Exam 2 - 100,000 points Book Title __________________________________________Section: 3a 3b 3c 3d Sample Exam A to F G to M N to S T to Z 01/23/2001•Rev.5State Any Assumptions You Need To Make -- Show All Work -- Circle Any Final AnswersUse Your Time Wisely - Work on What You Can - Be Sure to Write Down EquationsBOLDFACE Variables Are Vectors - Feel Free to Ask Any QuestionsResistance to Physics Tyranny! (50,000 pts.)1.) (a) The following circuit can be reduced to a single equivalent resistor by network reduction. At each stepin the reduction, circle the resistors you are going to reduce, mark them as SERIES or PARALLEL, then drawthe next equivalent circuit down to (and including) the final circuit. (b) If each of the resistors is 100. W, find the equivalent resistance of the circuit.Consider the following two RC circuits marked (I) and (II). In each case the resistors are 155 W and thecapacitors are 155 µF. (c) Calculate the time constant t for each circuit and circle the circuit which has theLARGER time constant.(I)(II)(d) Which of the RC circuits (I) or (II) has the larger initial current i0 ? Which has the larger maximum chargeQ0 ?(e) You are given two square metal plates with sides a = 10.0 cm. Design an air filled capacitor, such that whenhooked up to a 12.0 volt car battery and fully charged, it will spark across the gap and discharge. What is thecapacitance C of this badly designed capacitor? Do not say that the answer is zero… (grin).Physics 115 / Sample Exam 2 Winter 2001 Page 2Misdirection in Circuit Diagrams (50,000 points)2.) (a) A circuit dissipates 125 W of power. Find the current I that comes out of the 16.55 volt battery and theresistance R of the entire circuit.(b) The real battery V = 16.55 volts consists of a perfect battery with emf E and an internal resistance r = 1.00W. Find the electromotive force E .(c) The first two questions did not require you to solve this circuit – but now you will have to. This circuit canbe reduced to a single equivalent resistance, which we know above is R. If each of the resistors R1 through R5has a resistance A, then find A. If you did not get an answer to (a), use R = 100. W .(d) Since all the resistors are identical, which one(s) is/are the most vulnerable to burning out? And why?(e) The following circuit cannot be reduced by network reduction. There are two equations you would use tosolve this. Identify the currents and then write down BUT DO NOT SOLVE the Kirchhoff loop equation and theone other equation you would need to solve this circuit.Physics 115 / Sample Exam 2 Winter 2001 Page 3Not Everything Is As It Seems (50,000 points)3.) (a) Consider the six circuits on this page (A - F). Which of these circuits are really the same?(b) Which of these circuits can be solved with series/parallel network reduction? A B # D E F Circuit A Circuit BCircuit C Circuit DCircuit E Circuit F(c) If all the resistors are 100 W, find the current I that the battery is delivering in Circuit C. Show work either in margins on this pageor on the Worksheet at end of exam.(d) Consider a box of 10,000. identical 1000. W resistors. Find the equivalent resistance if they first are all connected in series, orthen if they are all connected in parallel.(e) Two light bulbs connected in parallel dissipate energy when plugged into 115 volts of 60.0 W and 15.0 W respectively. Ignoringany change of their resistance due to temperature, what is the power of these two bulbs when connected in series to the 115 volts.Physics 115 / Sample Exam 2 Winter 2001 Page 4X-Men! Mutants Rule… Courtesy of Hollywood and Marvel Comics (50,000 pts.)4.) (a) Storm (one of the good guys) is fighting Toad (one of the bad guys). After zappinghim with a lightning bolt, transferring a charge q = - 2.335 × 10-4 C, Toad (mass = 70.0kg) is accelerated at 10.0 m/s² in the +x direction. Find the magnitude and direction of theelectric field rE that Storm supplies to accelerate Toad.(b) After 2.00 seconds, when Toad is moving at 20.0 m/s, Toad’s boss Magneto (headbad guy) sends out a magnetic field, rB , to apply a magnetic force to cancel Storm’selectric force on Toad. Find the magnitude and direction of this B-field.(c) Can Magneto bring Toad to a stop in (b)? Briefly explain. If you write a long paragraph you’ll lose points.(d) Is the situation described in (b) a velocity selector for rvmsi=+20 0./$ as wedescribed in class? Briefly explain why or why not.(e) Storm stops the E-field and Magneto applies a new magnetic field ofrBTk=+400.$ on Toad moving at rvmsi=+20 0./$. Find the radius, r, of the turnthat Toad makes and the time, t, that it takes for him to make a 180° turn. (And headgood guy Professor Xavier