Answer
(Fatwa: 1034/761/L=1431)
If a woman goes out of home she should cover her body with burqa or chuddar in a way that no part of her body is exposed. This is the complete hijab. And if she put only dupatta (scarf) on head while the face is open, it is not complete hijab. In such case the woman shall be sinful. Almighty Allah says in the holy Quran:
يَا أَيُّهَا النَّبِيُّ قُل لِّأَزْوَاجِكَ وَبَنَاتِكَ وَنِسَاء الْمُؤْمِنِينَ يُدْنِينَ عَلَيْهِنَّ مِن جَلَابِيبِهِنَّ [الأحزاب : 59]
الجلباب فى اللغة التى خاطبنها بها رسول الله صلى الله عليه وسلم هو ما غطى جميع الجسم لا بد منه المحلى لابن حزم بحواله فقهى مقالات (4/50)
Allah (Subhana Wa Ta’ala) knows Best
Darul Ifta,
Darul Uloom Deoband