A magnetic field is uniform over a flat, horizontal circular region with a radius of $2\mathrm{.}00$ mm$,$ and the field varies with time. Initially the field is zero and then changes to $1\mathrm{.}50$ T$,$ pointing upward when viewed from above, perpendicular to the circular plane, in a time of $145$ ms$.$

$($a$)$

What is the average induced emf around the border of the circular region? $($Enter the magnitude in $$V and the direction as seen from above.$)$

magnitude $$V direction

as seen from above

$($b$)$

Immediately after this, in the next $75\mathrm{.}0$ ms$,$ the magnetic field changes to a magnitude of $0\mathrm{.}500$ T$,$ pointing downward when viewed from above. What is the average induced emf around the border of the circular region over this time period? $($Enter the magnitude in $$V and the direction as seen from above.$)$

magnitude $$V direction

as seen from above