Is 'iddah (waiting period) obligatory for a wife with whom the marriage has not been consummated, and is it permissible for her to marry immediately after divorce?

If a husband secludes himself with his wife in a proper seclusion where intercourse is possible, the majority of scholars hold that this seclusion carries the ruling of consummation. Thus, the waiting period (iddah) becomes obligatory upon divorce, even if the husband was unable to engage in intercourse due to illness. The waiting period concludes after three menstrual cycles for a menstruating woman, upon delivery for a pregnant woman, and after the passing of three months for a young girl who has not yet menstruated or an elderly woman who has despaired of menstruation.