Police officials said Rita Singh of Alauddin Chowk of Sonepur in Saran district had filed a bail-cancellation plea against her in-laws in the court.
She had been coming here for the last one week in this regard, and became angry when the district judge dismissed her petition.
"The district judge ducked as she threw the mobile phone. It went on to hit the bench or desk placed in front of him," said a source.
The policemen present around the court apprehended her and an FIR has been lodged at Pirbahore police station in the state capital.
"This is fallout of property dispute in her family. She had been opposing the bail plea of her in-laws and attacked the district judge after it was rejected," said Pirbahore SHO Nisar Ahmad.
Police said, the woman will be produced in the court and forwarded to jail.