A typical red blood cell subtends an angle of only when viewed at a persons near-point distance of 25 cm. Suppose a red blood cell is examined with a compound microscope in which the objective and eyepiece are separated by a distance of 12.0 cm. Given that the focal length of the eyepiece is 2.7 cm, and the focal length of the objective is 0.49 cm, nd the magnitude of the angle subtended by the red blood cell when viewed through this microscope.
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