VS =?

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Direction: Statement for :
In the circuit of fig. below the transistor parameters are V_TP = – 0.8 V and K_P = 200 µA/V²

V_S =?

1. 7.49 V
2. 6.41 V
3. 2.21 V
4. 4.53 V

Correct Option: C

Assume transistor in saturation
given, I_D = 0.4 mA
V_TP = – 0.8 V
k_P = 200 µA/V²
I_D = k_P [V_SG + (– V_TP)]²
0.4 × 10^–3 = 200 × 10^–6 [V_SG + 0.8]²
or [V_SG + 0.8]² = 2
or V_SG = √2 + 0.8 = 2.21 V
or V_SG = V_S – V_G = V_S – 0 = V_S
= 2.21 V