Answer:
0.85V
Explanation:
The emf is calculated by using the Lenz's Law
[tex]\epsilon=-\frac{\Delta\Phi_B}{\Delta t}[/tex]
But for this case we have that the magnetic field is constant. Hence we have
[tex]\epsilon=-\frac{B(A_{2}-A_{1})}{t_2-t_1}=-\frac{(1.10T)(0.270m^{2}-0.89m^{2})}{0.8s}\\\\\epsilon=0.85V[/tex]
where we have taken that the intial time is t1=0
I hope this is useful for you
regards