The expected answers were:
- For a bipolar junction transistor
β = α
1 - α
α = β
1+ β
Given that VBE = 0.6V
α= 0.98
VCC = IBRB + VBE +IERE
VCC = VCE + IcRC + IERE

β = α
1 - α
=
= 49

= 25.9µA
= 26µA
VCE = VCC - ICRC -ICRE
= VCC –IC(RC+RE)
= 12 – 1.27mA(5.6K + 1K)
VCE = 3.62V
IC = βIB = 49 x 25.9µA = 1.27µA
The question was on establishing the d.c. (operating point) parameters of a BJT connected in the common-emitter mode. It was quite popular with the candidates. However, the performance was about average.