Which of the following statement is/are correct:

i) MOSFET is insulated gate FET.

ii) MOSFET is a field-effect transistor whose drain current is controlled by the voltage applied at the gate terminal.

iii) In an enhancement type MOSFET (with n-type Source and drain regions), only with a positive voltage to a gate an 'Inversion layer' is formed and conduction takes place.

iv) The input resistance of a MOSFET is several orders of magnitude greater than that of JFET.