Answer
(a) $t=0.0s, 0.4s$ (b) $0.1s, 0.5s$
Work Step by Step
(a) The times at which the flux is maximized are at $t=0.0$ seconds and $t=0.4$ seconds. (b) The induced emf is equal to the negative change of flux in respect to time. This means that the emf is greatest when the downward sloping tangent line to the curve is the greatest. This is when $t=0.1s$ and $t=0.5s$.
