1) Threshold Voltage : The threshold voltage commonly abbreviated as Vth or Vgs of a field effect transistor (FET) is the minimum gate-to-source voltage differential that is needed to create a conducting path between the source and drain terminal.
2) Withstand Voltage : This is defined as the voltage which produce the loss of dielectric strength of an insulation. descriptive discharge voltage is a voltage at which the electrical stress in The insulation causes a failure
3) 100℅ flashover voltage : The voltage that causes a flash over at each of it is application under specified conditions, when applied to test objects as specified. this is known as 100% flashover voltage.
4) 50% flashover voltage : this is the voltage which has may be 50% flashover, when applied to a test object.
5) AC Test Voltage : Alternating test voltage of power frequency should have a frequency range of 40 to 60 Hz and should be approximately sinusoidal.
6) Creeping Distance : It is shortest distance on the contour of the external surface of the insulator unit
7) Impulse Voltage : impulse voltages are voltage which are characterized by peak value time to front and time to half the front and time to half the peak value after the peak.
8) Discruptive Discharge Voltage : this is defined as the voltage which produces the loss of dielectric strength of an insulation. Discruptive discharge voltage is a voltage at which the electrical stress in The insulation causes of failure