Sunlight enters a room at an angle of 32 above the horizontal and reects from a small mirror lying at on the oor. The reected light forms a spot on a wall that is 2.0 m behind the mirror, as shown in Figure 2642. If you now place a pencil under the
Chapter 23: Magnetic Flux and Faraday’s Law of Induction Flux=BAcos (thet) o Unit is Weber (Wb) o B is magnetic field o A is area Magnetic flux if used in the calculation of the induced emf Faraday’s Law: an emf is induced only when the magnetic flux though a loop changes with time Change∈ flux o Change∈time ) emf =−N ¿ Lenz’s law: an induced current always flows in the direction that opposes the change that caused it. Electric field caused by the motion of a rod: o E=Bv When a switch is added to a circuit and when the switch is closed, the current starts to increase immediately. As time goes on, the current increases more slowly and the potential difference across the inductor decrea