Question

In an ideal stable self – alpha cutoff frequency, what should be the current IBwith respect to IC?

(a) IB should be 20% of IC

(b) IB should be 5% of IC

(c) IB should be 10% of IC

(d) IB should be 50% of IC

The question was posed to me by my college professor while I was bunking the class.

The above asked question is from The Alpha Cutoff Frequency in chapter High Frequency Transistor of Electronic Devices & Circuits

Answer 1

Correct option is (c) IB should be 10% of IC

Easy explanation: Ideally, the resistor values are designed in a way that the voltage drop across RE is approximately 10% of Vcc and IB should be 10% of Ic. Hence, stable self – alpha cutoff frequency work best at low power supply voltages.