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Consider an electric motor. As we supply current to the motor, the coil starts to rotate. But, a rotating coil in a magnetic field results in an induced current. By Lenz’s Law, the induced current in the coil of a motor has to be in the direction opposite to the current that we put in, since otherwise, the motor would start to spin infinitely fast. We call this effect “back emf”, as the motor effectively acts like a battery that opposes current, as illustrated in Figure $$\PageIndex{1}$$