(1) Rape.  A male who has sexual intercourse with a female not his wife is guilty of rape if:

  (a) he compels her to submit by force or by threat of imminent death, serious bodily injury, extreme pain or kidnapping, to be inflicted on anyone;  or

  (b) he has substantially impaired her power to appraise or control her conduct by administering or employing without her knowledge drugs, intoxicants or other means for the purpose of preventing resistance;  or

  (c) the female is unconscious;  or

  (d) the female is less than 10 years old.

 Rape is a felony of the second degree unless (i) in the course thereof the actor inflicts serious bodily injury upon anyone, or (ii) the victim was not a voluntary social companion of the actor upon the occasion of the crime and had not previously permitted him sexual liberties, in which cases the offense is a felony of the first degree.

 (2) Gross Sexual Imposition.  A male who has sexual intercourse with a female not his wife commits a felony of the third degree if:

  (a) he compels her to submit by any threat that would prevent resistance by a woman of ordinary resolution;  or

  (b) he knows that she suffers from a mental disease or defect which renders her incapable of appraising the nature of her conduct;  or

  (c) he knows that she is unaware that a sexual act is being committed upon her or that she submits because she mistakenly supposes that he is her husband.