Consider a closed surface S surrounding volume V. If $$\overrightarrow{\mathrm r}$$ is the position vector of a point inside S, with $$\widehat n$$ the unit normal on S, the value of the integral is

Drift current in the semiconductors depends upon

For a BJT the common base current gain $$\alpha$$ = 0.98 and the collector base junction reverse bias saturation current I_CO = 0.6μA. This BJT is connected in the common emitter mode and operated in the active region with a base drive current I_B=20μA. The collector current IC for this mode of operation is

The channel resistance of an N-channel JFET shown in the figure below is 600 W when the full channel thickness (t_ch) of 10 μm is available for conduction. The built-in voltage of the gate P⁺N junction (V_bi) is -1 V. When the gate to source voltage (V_GS) is 0 V, the channel is depleted by 1 μm on each side due to the built in voltage and hence the thickness available for conduction is only 8 μm The channel resistance when V_GS = -3 V is