The pinch-down voltage of p-channel junction FET is V_P =5V and the drain-to-source saturation current I_{DSS} = −40 mA. The value of drain– source voltage V_{DS} is such that the transistor is operating in the saturated region. The drain current is given as I_D = 15 mA. Determine the gate–source voltage V_{GS}
(GATE 2001).