Figure below shows a curcuit diagram of JFET amplifier. Taking drain current (Id) =2.5 mA, Determine the:

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(a) Gate voltage, Vg

Soln

Gate voltage Vg = Voltage drop across resistor R2

Vg = {R2/(R1+R2) } x Vcc

      = {280000/(2000000+280000)} × 16 volts

      = 1.9649 volts

(b) Source Voltage Vs

Soln

Source voltage, Vs = Id ×Rs

         = (0.0025 x 1500)

         = 3.75 volts

(c) Gate to Source Voltage Vgs

Soln

Vgs = Vg - Id Rs

        = 1.9649 - 3.75

        = - 1.79 volts

(d) Drain Voltage, Vd

Soln

Drain voltage Vd = Id Rd

                               = (0.0025 x 2500)

                               = 6.25 volts

(e) Drain to source voltage ,Vds

Vds = Vdd - Id(Rd + Rs)

        = 16 - 0.0025( 2500 + 1500)

         = 6 volts

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