Digital/electronic alternatives of Paper based Answer Books

I am looking a complete and matured solution as an alternative of paper based answer books for students who are appearing in the exams of class 10 and 12.

I suppose there is a display device on which question papers will be displayed and a digital answer book which will be used by students by using specific pen. After submit the exam data will be transferred to PDFs which will be sent to the respective examiners by email.

Is there any such thing on the earth?