The graph in the fi gure shows the emf produced by a

Chapter , Problem 85

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The graph in the fi gure shows the emf produced by a generator as a function of time t. The coil for the generator has an area of A 5 0.15 m2 and consists of N 5 10 turns. The coil rotates in a fi eld of magnitude 0.27 T. Concepts: (i) Can the period of the rotating coil be determined from the graph? (ii) The emf produced by a generator depends on its angular frequency. How is the angular frequency of the coil related to its period? (iii) Starting at t 5 0 s, how much time is required for the generator to produce its peak emf? Express the answer in terms of the period T of the motion (e.g., t 5 (0.1) T). (iv) How often does the polarity of the emf change in one cycle? Calculations: (a) Determine the period of the motion. (b) What is the angular frequency of the rotating coil? (c) Find the value of the emf when t 5 1 4 T, where T denotes the period of the coil motion. (d) What is the emf when t 5 0.025 s?