flux linked is given by$\phi = E S\cos \theta$ here area is taken as a vector in the direction of normal hebce in the given case phi= 05*2*1/2=1/2H/m^2 Induced emf is $\epsilon= d \phi /dt$ here change flux is 1/2 H/m^2 hence induced emf is 1/2*1/5=0.1V