PHYS 2426 Engineering Physics II Problem 30.2 1. A uniform magnetic field increases with time according to B = 0.300 (mT)(2.00 (s-2)t2 + 3.00 (s-1)t + 5) (1) This field is directed out of the page and a circular wire loop of radius r = 0.250 m is located in the field region as shown in the figure. (a) Calculate the magnetic flux passing through the loop at time t = 0.50 s (b) Calculate the magnitude of the emf, &, induced around the loop at time t = 0.50 s. (c) Use Lenz's law to find the direction of the induced emf. The steps are: i. You should know the direction of the given field, call it Borig. ii. You also should know (or figure out) whether Boring or the flux is increasing or decreasing. Based on this, decide the direction of A Borig. (i) If Borig or the flux is increasing, then A Boring has the same direction as Borig itself. (ii) If Borig or the flux is decreasing, then Borig is opposite in direction to Borig. iii. Lenz's law states that the direction of Bind is always opposite to the di- rection of A Boring. Now you know the direction of Bind. iv. Use the right hand rule to find the direction of the induced current. The in- duced emf and the induced current are in the same direction. The direction is either CW or CCW.