3. Suppose a proton was found in a magnetic field of 0.25 T, undergoing circular motion with a radius of 0.82 cm. If the proton was initially found in a parallel plate set up below, starting at the positive plate from rest: a. Determine the potential difference through the plates in order to have observed the circular motion. (3 marks) b. How would the circular orbit have changed if the magnetic field strength doubled? Explain in 2 sentences. (2 marks) X X X X XXXXX + + + + + + + X XXXX XXXX - X X E= 0. 25T