The fee is a one-time fee for persons applying for F, J or M visas and covers the costs of administering SEVIS (the Student and Exchange Visitor Information System). This fee is charged in addition to the applicable visa application fee. The SEVIS fee has been set at $200 for most applicants.Certain short-term exchange visitors (au pairs, summer work/travel and camp counselors) will pay a reduced fee of $35. Persons sponsored by the U.S. Government are exempt from the fee.owever, persons with I-20/DS-2019 forms issued before that date are not subject to the SEVIS fee regardless of when they apply for their visa. Applicants with F-1, F-3, J-1, M-1 and M-3 visas) will have to pay the SEVIS fee.
A relay is an electrically operated switch. Many relays use an electromagnet to mechanically operate a switch, but other operating principles are also used, such as solid-state relays.
A mercury relay (mercury displacement relay, mercury contactor) is a relay that uses mercury as the switching element.They are used as high-current switches or contactors, where contact erosion from constant cycling would be a problem for conventional relay contacts.he mercury relay thus allows for switching of higher currents with a small control current for a large number of cycles. They are often installed into automatic controllers that required extended periods of unattended continuous switching operation.