Problem 1. Calculate the flux A square loop of wire 10.0 cm on a side is in a 1.25 T magnetic field B. What are the maximum and minimum values of flux that can pass through the loop? Approach The flux is given by Eq. 2 (OB = BAcos@). It is a maximum for 0 =0, which occurs when the plane of the loop is perpendicular to B . The minimum value occurs when 0 = 90 and the plane of the loop is aligned with B . Problem 2. Change in flux and induced emf A coil of wire is situated in a 0.5 T uniform magnetic field. The area of the coil is 2.0 m2. (a) What is the magnetic flux if the angle between the magnetic field and the normal to the surface of the coil is 60? (b) After 5 s, the magnetic field is now parallel to the normal to the surface. What is the induced emf? Approach (a) The angle between the magnetic field and the normal to the surface of the coil is 60 (b) The angle between the magnetic field and the normal to the surface of the coil is 0, because the magnetic field is now parallel to the normal surface