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.
Relays are used to isolate one voltage level from another. A PLC may be used to control the operation of a medium-voltage motor, perhaps 2,300V or 4,160V. A relay is used to energize the starter, which, in turn, switches the motor voltage while the PLC controls the relay.