H-zone in a contracted sarcomere differ from that of a relaxed sarcomere . Yes its true because H-zone is narrower in contracted sarcomere. The functional unit of striated muscle is sarcomere. Sarcomere is the very basic unit of skelatal muscle. Between two Z line sarcomere is the repeated unit .Hence we can say that H-zone in a contracted sarcomere differ from that of a relaxed sarcomere.
