Question

compared to the Bay of Bengal islands the Arabian Sea Islands receive less rainfall

Answer 1

because on reaching arabian sea do not have enough water in them.. because moving through plains and ghats the loose their moisture
  
hope satisfied

Answer 2

arabian sea island are flat islands which do not hve hills that causes topographical rain and mreover their vegetation is not so dense.
so,arabian sea island receives less rainfall as compare to bay of bengal islands.