v a '5' - - - PhySiCS 1508 Spring 2023 Hi, Tiffany v Sign Out ' HEIF :S Course Home ( HW Ch 21 (Mastering) Practice Problem 21.07 Let us apply the concepts of motional emf and Lenz's law to a slidewire generator. Suppose the length L of the slide-wire rod in (59m) is 0.10 m , its speed I) is 2.5 m/s. the total resistance of the loop is 0.030 (land B is 0.60 T. Find the emi, 8, the induced current, the force acting on the rod, and the mechanical power needed to keep the rod moving at constant speed. Figure 10H >00; - Revtew l Constants SOLUTION SET UP AND SOLVE To find the emf, we use 5 = 'UBL: E : uBL = (2.5 m/s)(0.60 T)(0.10 m) = 0.15 V From Ohm's law, the current in the loop is I : S/R : (0.15 V)/(D.030 (I) : 5.0 A Lenz's law tells us that an induced lorce acts on the rod, opposite to the rod's direction of motion. The magnitude of this force is Financed : ILB : (5.0 A)(0.10 m)(0.60 T) 2 0.30 N To keep the rod moving at constant speed. a torce equal in magnitude and opposite in direction to mduwd must act on the rod' Theretore, the mechanical power P needed to keep the rod moving is P = Financed?) = (0.30 N)(2.5 m/s) = 0.75 W REFLECT The expression for the emf is the same result we found trom Faraday's law. The rate at which the induced emf delivers electrical energy to the circuit is P : 51 : (0.15 V)(5.0 A) : 0.75 w This is equal to the mechanical power input. Finance\Physics 150B Spring 2023 Hi, Tiffany Sign Out Help Course Home Review | Constants electrical energy. Finally, the rate of dissipation of electrical energy in the circuit resistance is P = 12 R = (5.0 A)2 (0.030 $2) = 0.75 W Let us apply the concepts of motional emf and Lenz's law which is also to be expected. to a slide-wire generator. Suppose the length L of the slide-wire rod in (Figure 1) is 0.10 m , its speed v is 2.5 m/s, the total resistance of the loop is 0.030 0,and B is 0.60 T. Find the emf, &, the induced current, the Part A - Practice Problem: force acting on the rod, and the mechanical power needed to keep the rod moving at constant speed. If L = 0.14 m, v = 2.5 m/s, the total resistance of the loop is 0.025 $2, and B = 0.35 T, find the rate at which the induced emf delivers electrical energy to the circuit. Figure Pearson