The University of Iowa is weighing an idea to charge all undergraduates an extra $30 a year to encourage more of them to study abroad. The fee, if ultimately approved by UI leadership and the Board of Regents, would generate about $770,000 a year. That would boost study abroad support about 66 percent, according to Downing Thomas, associate provost and dean of International Programs. “Unlike any other fee, 100 percent of the revenue would go back to students in the form of scholarships,” he told faculty leaders this week in presenting the idea.