The magnetic field shown in the figure has a uniform magnitude

The magnetic field shown in the figure has a uniform magnitude of 25.0 mT directed into the paper. The initial diameter of the kink is 2.00 cm. (a) The wire is quickly pulled taut, and the kink shrinks to a diameter of zero in 50.0 ms. Determine the average voltage induced between endpoints A and B. Include the polarity. (b) Suppose the kink is undisturbed, but the magnetic field increases to 100 mT in 4.00 x 10^-3 s. Determine the average voltage across terminals A and B, including polarity, during this period.