NMOS as Linear Resistance evaluator uses Linear Resistance = Length of the Channel/(Mobility of Electrons at Surface of Channel*Oxide Capacitance*Width of Channel*(Gate Source Voltage-Threshold Voltage)) to evaluate the Linear Resistance, The NMOS as linear resistance acts as a variable resistor in the linear region and as a current source in the saturation region. Unlike a BJT, to use a MOSFET as a switch, you need to operate within the linear region. Linear Resistance is denoted by rDS symbol.
How to evaluate NMOS as Linear Resistance using this online evaluator? To use this online evaluator for NMOS as Linear Resistance, enter Length of the Channel (L), Mobility of Electrons at Surface of Channel (μn), Oxide Capacitance (Cox), Width of Channel (Wc), Gate Source Voltage (Vgs) & Threshold Voltage (VT) and hit the calculate button.