Okay guys .....so i'am stuck in a very simple thing but can't figure it out...the problem is this..
 
There is a taut stretched conducting wire between two rigid supports in the x-y plane (see the img file attached !!) and a uniform(constant) magnetic field of magnitude B exists along the negative z-axis.Now the wire is plucked so that it vibrates (obviously the vibrations produced are Standing or Stationary following the equation y=2Asin(kx)cos (wt) )in the 3rd harmonic.I have to calculate the max e.m.f developed.Now ive already worked out the area of the loops produced(by integrating the Standing wave function i.e. finding the area under the curve but i'am stuck at obtaining the length of the string in terms of the already given parameters(i've already tried 3lambda/2 = Length of the wire)...and it's soo frustrating...pls point out my blunder guys