yes emf is proporional to rate of change of flux linkage
Ok so we can see that for the first section of the graph the emf will be 0 as the coil is not in the magnetic field.
In part (i) we found that at t=0.2s the emf is 80mV. We are told that the coil is moving at 0.1m/s and it's 0.02m wide, so the flux linkage will continue to change until the whole coil is inside the magnetic field, which would be at t=0.04
Then the emf will drop to 0 again as the flux linkage won't be changing as the coil moves through the field. then think about what would happen as the coil leaves the field.
Ok so we can see that for the first section of the graph the emf will be 0 as the coil is not in the magnetic field.
In part (i) we found that at t=0.2s the emf is 80mV. We are told that the coil is moving at 0.1m/s and it's 0.02m wide, so the flux linkage will continue to change until the whole coil is inside the magnetic field, which would be at t=0.04
Then the emf will drop to 0 again as the flux linkage won't be changing as the coil moves through the field. then think about what would happen as the coil leaves the field.