Is obeying the husband by not attending Quranic study circles of greater reward than learning the Quran, especially if the husband believes this is due to his wife not wearing the niqab?

It is not permissible for a wife to leave her husband's house without his permission, except in cases of necessity. Her obedience to him in determining the frequency of her outings to learn the Quran takes precedence over increasing her learning. Regarding the niqab, the wife must obey her husband if he orders her to wear it, even if scholars differ on its obligation.