Transistor — Saturation CheckHardQuestion 20258
Question
A BJT with β = 200 has I_B = 60 μA and V_CC = 9 V, R_C = 1 kΩ. Is it in saturation?
- ANo — I_C = 12 mA would exceed I_C,sat = 9 mA, so yes, saturatedCorrect
- BYes and V_CE = 0
- CNo — active region
- DYes — V_CE = 9 V
Correct answer
No — I_C = 12 mA would exceed I_C,sat = 9 mA, so yes, saturated
Explanation
Active I_C = β×I_B = 200×60μA = 12 mA. Maximum possible: I_C,sat = V_CC/R_C = 9/1000 = 9 mA. Actual I_B required for saturation: I_B,sat = I_C,sat/β = 9mA/200 = 45 μA < 60 μA. Since I_B > I_B,sat → transistor is saturated. V_CE,sat ≈ 0.2 V.