“.............. A mentally challenged girl cannot legally give a consent which would necessarily involve understanding of the effect of such consent. It has to be a conscious and voluntary act. There is a gulf of difference between consent and submission. Every consent involves a submission but the converse does not follow, and mere act of submission does not involve consent. An act of helpless resignation in the face of inevitable compulsion, quiescence, non-resistance or passive giving-in when the faculty is either clouded by fear or vitiated by duress or impaired due to mental retardation or deficiency cannot be considered to be consent as understood in law. For constituting consent, there must be exercise of intelligence based on the knowledge of the significance and the moral effect of the act. A girl whose mental faculties are undeveloped, , cannot be said in law, to have suffered sexual intercourses with consent.”