Question

VS=100V, R=1kΩ, and the transistor parameter f=1mAV3. The amplifier is biased with VIN=4V.
1.)What is the dc operating point (bias) output voltage VOUT (in Volts) of this amplifier?
2.)What is the small signal gain (vOUTvIN) of this amplifier when it is biased as above?

Answer 1

Please ome one reply with formulae

Answer 2

1.) VS-(R*iD)
where iD=f*(VIN)^3
and f is in A/V^3
so that,
VS-(R*(f*(VIN)^3))

Just make you convert f to A/V^3 ; if you plug in .001 you will get a good answer if you plug in 1 you will get the wrong answer.

In your case i believe the answer is 36 which i got from 100-(1000*(.001*(4)^3))

Answer 3

2.) -3*f*(Vin^2)*R
where f is in A/V^3
and R is in ohms (both like number one)

In your case i believe it's -48: -3*.001*(4^2)*1000