Question

In the circuit shown below, β =100 and VBE=0.7V. The Zener diode has a breakdown voltage of 6V. Find the operating point.

(a) (6.7V, 5.3mA)

(b) (5.7V, 5.3mA)

(c) (6.7V, 5mA)

(d) (6V, 5mA)

The question was asked by my college director while I was bunking the class.

The above asked question is from Problems on AC and DC Analysis in division Small-Signal Low-Frequency AC models of Transistors of Electronic Devices & Circuits

Answer 1

Correct answer is (a) (6.7V, 5.3mA)

Best explanation: We know, by KVL -12+(IC+IB)1K+6+VBE=0

We have IE=5.3. IC= αIE=5.24mA. From another loop, -12+IEIK+VBE=0

We have, hoe=12-5.3m*1000=6.7V. Hence the Q point is (6.7V, 5.3mA).